tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it./home/user/instruction.md
1 # Implement the line diff (minimal canonical edit script) 2 3 ## Context 4 `diff-patch-engine` is the line-level diff/patch building block behind our 5 `git diff`-style tooling and three-way merges (TypeScript, Node 20). It computes 6 an ordered edit script between two sequences of lines and can replay that script 7 onto the original to reproduce the target. 8 9 `applyPatch(original, edits)` (the diff's own verifier), `diffStats`, and the 10 `splitLines` / `joinLines` text helpers are all provided and must not be 11 changed. **Only `diff(a, b)` is unimplemented.** 12 13 ## Your task 14 Implement `src/diff/myers.ts` → `diff(a: string[], b: string[]): Edit[]`, 15 returning an ordered list of `eq` / `del` / `ins` edits (see `Edit` / `EditOp` 16 in `types.ts`). The returned script is graded against three independent 17 properties , **validity**, **minimality**, and a **canonical tie-break** , and 18 must satisfy all three for every input. Being valid and minimal is *not* 19 sufficient: a uniquely determined script is required and any other minimal 20 script is graded wrong. 21 22 Each op consumes lines as follows: an `eq` consumes one line from each side and 23 those two lines are equal; a `del` consumes one line from `a`; an `ins` consumes 24 one line from `b`. 25 26 ### 1. Validity 27 `applyPatch(a, diff(a, b))` must deep-equal `b`. Equivalently, both of these 28 hold simultaneously: 29 - the subsequence of `eq` + `del` lines, in order, equals `a`; 30 - the subsequence of `eq` + `ins` lines, in order, equals `b`; 31 32 and every `eq` carries a line equal to the line it consumes on each side. 33 34 ### 2. Minimality 35 Among all valid scripts, the returned one must use the fewest non-`eq` ops. Let 36 `C(a, b)` be the maximum possible number of `eq` ops over all valid scripts for 37 the pair (equivalently, the length of the longest common subsequence of `a` and 38 `b`). Then the script must have exactly `C(a, b)` `eq` ops and exactly 39 `a.length + b.length - 2 * C(a, b)` non-`eq` ops (`del` + `ins`). This is what 40 makes the result a *diff* rather than "delete all of `a`, then insert all of 41 `b`". 42 43 ### 3. Canonical tie-break (the crux) 44 Many distinct valid, minimal scripts can exist for one pair. Exactly one of them 45 is canonical, and that is the one you must return. The canonical script is the 46 unique valid, minimal script characterised by the following property, applied to 47 the script read left to right. 48 49 > Consider the script as a left-to-right interleaving of `a` and `b`. Walk a 50 > pair of cursors `(i, j)` , `i` into `a`, `j` into `b` , both starting at the 51 > first line. At each step the next op of the script decides which cursor(s) 52 > advance: `del` advances `i`, `ins` advances `j`, `eq` advances both (and 53 > requires `a[i] === b[j]`). 54 > 55 > Call an op **length-preserving at `(i, j)`** if the script can still be 56 > completed, from the resulting cursor position, into a valid script that meets 57 > the minimality bound of clause 2 for the whole pair. The canonical script is 58 > the one that, at every step, makes the **highest-priority length-preserving 59 > choice** under this fixed priority order: 60 > 61 > 1. `del` of `a[i]` , chosen whenever it is length-preserving at `(i, j)`; 62 > 2. otherwise `ins` of `b[j]` , chosen whenever it is length-preserving at 63 > `(i, j)`; 64 > 3. otherwise `eq` of the shared line (this case forces `a[i] === b[j]`). 65 > 66 > When `i` has reached the end of `a`, only `ins` remains; when `j` has reached 67 > the end of `b`, only `del` remains; when both are at the end, the script ends. 68 69 The grader pins this exact script; any other valid, minimal, but 70 differently-resolved script is rejected. 71 72 ## Edge cases to get right 73 - `a` and `b` equal → all `eq`, no `del`/`ins`. 74 - `a` empty → every line of `b` as `ins`, in order. 75 - `b` empty → every line of `a` as `del`, in order. 76 - both empty (`[]`) → `[]`. 77 - Lines are compared by exact string equality only , no Unicode normalization, 78 no trimming. Lines containing whitespace, tabs, emoji, combining characters, 79 newline characters, or text that looks like an op name are opaque values. 80 - Callers diffing text use `splitLines`, so a trailing newline appears as a 81 final `""` entry and must be preserved verbatim. The empty string is `[""]` 82 (length 1), never `[]`. 83 - The same `(a, b)` must always produce the identical script (determinism). 84 85 ## Performance & memory 86 Inputs can be large , up to ~100,000 lines , and are frequently *largely 87 identical*: two revisions of the same file, sharing long common runs at the 88 start, the end, or both. Your implementation must use memory **proportional to 89 the input size** on such inputs. Allocating a full `n × m` dynamic-programming 90 table is `Θ(n·m)` memory and will **exhaust the available memory on large 91 inputs , that is graded as a failure**. The constraint only bites at scale: 92 small inputs may be handled however you like. Time should stay within a few 93 seconds even for the largest inputs. 94 95 ## Definition of done 96 `npm run typecheck` is clean and `npm test` passes. Implement `diff` only , do 97 not modify `applyPatch`, the text helpers, the types/errors, or the tests. 98
/home/user/app/src/diff/types.ts
1 /**
2 * Types for the line-oriented diff + patch engine.
3 *
4 * A diff is an **edit script**: an ordered list of operations that, replayed
5 * against the original sequence of lines, reproduces the target sequence.
6 *
7 * - `eq` , a line present in BOTH sides; consumes one line from the original
8 * and one from the target (they are equal).
9 * - `del` , a line present only in the original; consumes one line from the
10 * original (it is removed).
11 * - `ins` , a line present only in the target; consumes one line from the
12 * target (it is added).
13 *
14 * The engine works on `string[]` (one entry per line); {@link splitLines} /
15 * {@link joinLines} convert to and from a single text blob.
16 */
17
18 export type EditOp = "eq" | "del" | "ins";
19
20 /** A single edit-script entry: an operation paired with the line it concerns. */
21 export interface Edit {
22 op: EditOp;
23 /** For `eq`/`del` this is the original line; for `ins` it is the new line. */
24 line: string;
25 }
26
27 /** Aggregate counts over an edit script (handy for tests and stats). */
28 export interface DiffStats {
29 eq: number;
30 del: number;
31 ins: number;
32 }
33/home/user/app/src/diff/myers.ts
1 import type { Edit } from "./types.js";
2
3 /**
4 * Compute the canonical minimal line-level edit script transforming `a` into `b`.
5 *
6 * Return an ordered `Edit[]` that, replayed against `a` by `applyPatch`,
7 * reproduces `b`. An `eq` consumes one line from each side (the lines are
8 * equal); a `del` consumes one line from `a`; an `ins` consumes one line from
9 * `b`. (See `EditOp` in types.ts.) The script must satisfy ALL THREE of the
10 * following; each is checked independently and validity + minimality is NOT
11 * sufficient.
12 *
13 * 1. VALID , `applyPatch(a, diff(a, b))` deep-equals `b`. Equivalently the
14 * `eq`+`del` lines (in order) equal `a`, the `eq`+`ins` lines equal `b`, and
15 * every `eq` carries a line equal to the one it consumes on each side.
16 * 2. MINIMAL , fewest non-`eq` ops of any valid script. With `C(a,b)` = the
17 * maximum achievable number of `eq` ops (the LCS length), the script has
18 * exactly `C(a,b)` `eq` ops and `a.length + b.length - 2*C(a,b)` non-`eq` ops.
19 * 3. CANONICAL , among the (often many) valid minimal scripts, return THE one
20 * defined below; the same `(a,b)` always yields it.
21 *
22 * The canonical script (the crux): read it left to right as an interleaving of
23 * `a` and `b`, walking cursors `(i, j)` from the start , `del` advances `i`,
24 * `ins` advances `j`, `eq` advances both (and requires `a[i] === b[j]`). Call an
25 * op *length-preserving at `(i, j)`* if, after taking it, the script can still be
26 * completed from the new position into a valid script meeting the clause-2
27 * minimality bound. At every step take the highest-priority length-preserving
28 * choice under this fixed priority:
29 * (1) `del` of `a[i]` if length-preserving at `(i, j)`;
30 * (2) else `ins` of `b[j]` if length-preserving at `(i, j)`;
31 * (3) else `eq` of the shared line (this case forces `a[i] === b[j]`).
32 * When `i` is at the end of `a` only `ins` remains; when `j` is at the end of
33 * `b` only `del` remains; when both are at the end the script ends.
34 *
35 * Edge cases: equal inputs -> all `eq`; empty `a` -> all `ins`; empty `b` -> all
36 * `del`; both empty -> `[]`. Lines compare by exact string equality only (no
37 * normalization/trimming); whitespace, tabs, emoji, combining chars and embedded
38 * newlines are opaque. A trailing newline shows up via `splitLines` as a final
39 * `""` and must be preserved; the empty string is `[""]` (length 1), never `[]`.
40 *
41 * Performance & memory: inputs may be large (up to ~1e5 lines) and are often
42 * largely identical (long shared runs at the start and/or end). Use memory
43 * proportional to the input size , allocating a full `n*m` table (Θ(n·m) memory)
44 * exhausts memory on large inputs and is graded as a failure. Small inputs may
45 * be handled any way; the constraint only bites at scale.
46 */
47 export function diff(a: string[], b: string[]): Edit[] {
48 // TODO(diff): implement the contract documented above. This stub throws so the
49 // engine is wired but non-functional; the suite must fail until implemented.
50 void a;
51 void b;
52 throw new Error("diff not implemented");
53 }
54ls && echo "---" && ls src/diff && echo "---" && cat package.json
README.md
node_modules
package-lock.json
package.json
src
test
tsconfig.json
vitest.config.ts
---
errors.ts
myers.ts
patch.ts
text.ts
types.ts
---
{
"name": "diff-patch-engine",
"version": "0.2.0",
"private": true,
"description": "Line-oriented diff (minimal LCS edit script) and patch-apply engine.",
"type": "module",
"engines": {
"node": ">=20"
},
"scripts": {
"build": "tsc -p tsconfig.json",
"typecheck": "tsc -p tsconfig.json --noEmit",
"test": "vitest run",
"test:watch": "vitest"
},
"devDependencies": {
"@types/node": "20.14.10",
"typescript": "5.5.3",
"vitest": "1.6.0"
}
}/home/user/app/src/diff/patch.ts
/home/user/app/src/diff/text.ts
1 /**
2 * Text <-> lines conversion for the diff engine.
3 *
4 * `splitLines` splits on "\n" and keeps every line as a separate entry. A
5 * trailing newline yields a final empty entry preserved by `joinLines`, so the
6 * round-trip `joinLines(splitLines(t)) === t` holds for any input (including the
7 * empty string, which becomes `[""]`).
8 *
9 * Provided complete.
10 */
11 export function splitLines(text: string): string[] {
12 return text.split("\n");
13 }
14
15 export function joinLines(lines: string[]): string {
16 return lines.join("\n");
17 }
181 import { PatchError } from "./errors.js";
2 import type { DiffStats, Edit } from "./types.js";
3
4 /**
5 * Apply an edit script to `original`, returning the patched line sequence.
6 *
7 * Replays the script left to right against a cursor into `original`:
8 *
9 * - `eq` , the next original line must EQUAL `edit.line`; emit it and advance
10 * the cursor. A mismatch (or running off the end) is a
11 * `PatchError("context_mismatch" | "unexpected_end")`: the patch does not
12 * apply to this input.
13 * - `del` , the next original line must equal `edit.line`; advance the cursor
14 * WITHOUT emitting (the line is removed). Same error rules as `eq`.
15 * - `ins` , emit `edit.line`; the cursor does NOT advance (nothing consumed
16 * from the original).
17 *
18 * After the script, every original line must have been consumed; leftover lines
19 * are a `PatchError("trailing_lines")`. An unrecognised op is
20 * `PatchError("unknown_op")`.
21 *
22 * This is the inverse of {@link diff}: for any `a`, `b`,
23 * `applyPatch(a, diff(a, b))` must deep-equal `b`. Provided complete , the diff
24 * you implement is validated against this applier.
25 */
26 export function applyPatch(original: string[], edits: Edit[]): string[] {
27 const out: string[] = [];
28 let i = 0; // cursor into `original`
29
30 for (const edit of edits) {
31 switch (edit.op) {
32 case "eq": {
33 if (i >= original.length) {
34 throw new PatchError("unexpected_end", `eq past end of original at op consuming "${edit.line}"`);
35 }
36 if (original[i] !== edit.line) {
37 throw new PatchError(
38 "context_mismatch",
39 `eq mismatch at original line ${i}: expected "${edit.line}", found "${original[i]}"`,
40 );
41 }
42 out.push(original[i] as string);
43 i++;
44 break;
45 }
46 case "del": {
47 if (i >= original.length) {
48 throw new PatchError("unexpected_end", `del past end of original at op removing "${edit.line}"`);
49 }
50 if (original[i] !== edit.line) {
51 throw new PatchError(
52 "context_mismatch",
53 `del mismatch at original line ${i}: expected "${edit.line}", found "${original[i]}"`,
54 );
55 }
56 i++;
57 break;
58 }
59 case "ins": {
60 out.push(edit.line);
61 break;
62 }
63 default: {
64 throw new PatchError("unknown_op", `unknown edit op: ${String((edit as Edit).op)}`);
65 }
66 }
67 }
68
69 if (i !== original.length) {
70 throw new PatchError(
71 "trailing_lines",
72 `patch consumed ${i} of ${original.length} original lines; ${original.length - i} left over`,
73 );
74 }
75 return out;
76 }
77
78 /** Tally an edit script by op kind. Provided complete. */
79 export function diffStats(edits: Edit[]): DiffStats {
80 const stats: DiffStats = { eq: 0, del: 0, ins: 0 };
81 for (const e of edits) stats[e.op]++;
82 return stats;
83 }
84cat /home/user/app/src/diff/errors.ts; echo "==== TEST DIR ===="; ls -la /home/user/app/test; echo "===="; cat /home/user/app/tsconfig.json; echo "==== vitest ===="; cat /home/user/app/vitest.config.ts
/**
* Typed errors for the diff/patch engine. A single class with a stable `code`
* discriminator keeps call sites and tests decoupled from message wording.
*/
export type PatchErrorCode =
| "context_mismatch"
| "unexpected_end"
| "trailing_lines"
| "unknown_op";
export class PatchError extends Error {
readonly code: PatchErrorCode;
constructor(code: PatchErrorCode, message: string) {
super(message);
this.name = "PatchError";
this.code = code;
Object.setPrototypeOf(this, PatchError.prototype);
}
}
==== TEST DIR ====
total 8
drwxr-xr-x 2 user user 60 Jun 21 13:09 .
drwxr-xr-x 5 user user 4096 Jun 21 13:09 ..
-rw-r--r-- 1 user user 1009 Jun 20 08:36 patch.test.ts
====
{
"compilerOptions": {
"target": "ES2022",
"module": "ESNext",
"moduleResolution": "Bundler",
"lib": ["ES2022"],
"types": ["node"],
"rootDir": ".",
"outDir": "dist",
"strict": true,
"noUnusedLocals": true,
"noUnusedParameters": true,
"noImplicitReturns": true,
"noFallthroughCasesInSwitch": true,
"exactOptionalPropertyTypes": false,
"esModuleInterop": true,
"forceConsistentCasingInFileNames": true,
"resolveJsonModule": true,
"skipLibCheck": true,
"verbatimModuleSyntax": false
},
"include": ["src", "test"],
"exclude": ["node_modules", "dist"]
}
==== vitest ====
import { defineConfig } from "vitest/config";
export default defineConfig({
test: {
environment: "node",
include: ["test/**/*.test.ts"],
reporters: ["default"],
testTimeout: 10_000,
hookTimeout: 10_000,
},
});mkdir -p /tmp/scratch && cat > /tmp/scratch/ref.mjs <<'EOF'
// Reference canonical via suffix-LCS DP (trusted), plus experiments.
function applyPatch(original, edits){
const out=[]; let i=0;
for(const e of edits){
if(e.op==="eq"){ if(original[i]!==e.line) throw new Error("eq mismatch"); out.push(original[i]); i++; }
else if(e.op==="del"){ if(original[i]!==e.line) throw new Error("del mismatch"); i++; }
else if(e.op==="ins"){ out.push(e.line); }
}
if(i!==original.length) throw new Error("trailing");
return out;
}
// suffix LCS DP canonical (no trim)
function canonicalDP(a,b){
const na=a.length, nb=b.length;
const W=nb+1;
const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--){
for(let j=nb-1;j>=0;j--){
if(a[i]===b[j]) L[i*W+j]=L[(i+1)*W+(j+1)]+1;
else { const d=L[(i+1)*W+j], s=L[i*W+(j+1)]; L[i*W+j]= d>=s?d:s; }
}
}
const out=[]; let i=0,j=0;
while(i<na || j<nb){
if(i<na && L[i*W+j]===L[(i+1)*W+j]){ out.push({op:"del",line:a[i]}); i++; }
else if(j<nb && L[i*W+j]===L[i*W+(j+1)]){ out.push({op:"ins",line:b[j]}); j++; }
else { out.push({op:"eq",line:a[i]}); i++; j++; }
}
return out;
}
// candidate: trim common prefix + suffix then DP core
function canonicalTrim(a,b){
const na=a.length, nb=b.length;
let p=0; while(p<na && p<nb && a[p]===b[p]) p++;
let s=0; while(s<na-p && s<nb-p && a[na-1-s]===b[nb-1-s]) s++;
const ca=a.slice(p,na-s), cb=b.slice(p,nb-s);
const core=canonicalDP(ca,cb);
const out=[];
for(let k=0;k<p;k++) out.push({op:"eq",line:a[k]});
for(const e of core) out.push(e);
for(let k=na-s;k<na;k++) out.push({op:"eq",line:a[k]});
return out;
}
// candidate: trim suffix only
function canonicalSuffixTrim(a,b){
const na=a.length, nb=b.length;
let s=0; while(s<na && s<nb && a[na-1-s]===b[nb-1-s]) s++;
const ca=a.slice(0,na-s), cb=b.slice(0,nb-s);
const core=canonicalDP(ca,cb);
const out=[];
for(const e of core) out.push(e);
for(let k=na-s;k<na;k++) out.push({op:"eq",line:a[k]});
return out;
}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
// random test
function randSeq(maxLen, alpha){
const n=Math.floor(Math.random()*(maxLen+1));
const out=[];
for(let i=0;i<n;i++) out.push(String.fromCharCode(97+Math.floor(Math.random()*alpha)));
return out;
}
let badTrim=0, badSuffix=0, total=0, validFail=0;
for(let t=0;t<200000;t++){
const a=randSeq(7,3), b=randSeq(7,3);
total++;
const ref=canonicalDP(a,b);
// validity check of ref
if(!eq(applyPatch(a,ref), b)) { validFail++; console.log("REF INVALID", a,b,ref); break; }
const tr=canonicalTrim(a,b);
if(!eq(tr,ref)) { if(badTrim<5) console.log("TRIM DIFF a=",JSON.stringify(a),"b=",JSON.stringify(b),"\n ref=",ref.map(e=>e.op+e.line).join(","),"\n trim=",tr.map(e=>e.op+e.line).join(",")); badTrim++; }
const su=canonicalSuffixTrim(a,b);
if(!eq(su,ref)) { if(badSuffix<5) console.log("SUFFIX DIFF a=",JSON.stringify(a),"b=",JSON.stringify(b)); badSuffix++; }
}
console.log({total, validFail, badTrim, badSuffix});
EOF
node /tmp/scratch/ref.mjsTRIM DIFF a= ["a","b","b"] b= ["a","b","a"]
ref= eqa,delb,eqb,insa
trim= eqa,eqb,delb,insa
TRIM DIFF a= ["a","b","b","b","c","a"] b= ["a","b","b","b","b","a","b"]
ref= eqa,insb,eqb,eqb,eqb,delc,eqa,insb
trim= eqa,eqb,eqb,eqb,delc,insb,eqa,insb
TRIM DIFF a= ["b","c","b","b","c","a"] b= ["b"]
ref= delb,delc,delb,eqb,delc,dela
trim= eqb,delc,delb,delb,delc,dela
TRIM DIFF a= ["a","a","a","a","c","a"] b= ["a","c","b"]
ref= dela,dela,dela,eqa,eqc,dela,insb
trim= eqa,dela,dela,dela,eqc,dela,insb
TRIM DIFF a= ["b","b","b","c","b","a","b"] b= ["b","b","a","b","a","c","b"]
ref= delb,eqb,eqb,delc,insa,eqb,eqa,insc,eqb
trim= eqb,eqb,delb,delc,insa,eqb,eqa,insc,eqb
{ total: 200000, validFail: 0, badTrim: 34179, badSuffix: 0 }cat > /tmp/scratch/ref2.mjs <<'EOF'
function applyPatch(o,edits){const out=[];let i=0;for(const e of edits){if(e.op==="eq"){if(o[i]!==e.line)throw 0;out.push(o[i]);i++;}else if(e.op==="del"){if(o[i]!==e.line)throw 0;i++;}else out.push(e.line);}if(i!==o.length)throw 1;return out;}
function canonicalDP(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
// safe prefix length per candidate rule, then DP on core
function trimDiff(a,b,prefixLen){
const na=a.length,nb=b.length;
let s=0;while(s<na-prefixLen&&s<nb-prefixLen&&a[na-1-s]===b[nb-1-s])s++;
const ca=a.slice(prefixLen,na-s),cb=b.slice(prefixLen,nb-s);
const core=canonicalDP(ca,cb);const out=[];
for(let k=0;k<prefixLen;k++)out.push({op:"eq",line:a[k]});
for(const e of core)out.push(e);
for(let k=na-s;k<na;k++)out.push({op:"eq",line:a[k]});
return out;
}
// Rule A: prefix while value unique in a AND unique in b
function ruleA(a,b){
const ca=new Map(),cb=new Map();
for(const x of a)ca.set(x,(ca.get(x)||0)+1);
for(const x of b)cb.set(x,(cb.get(x)||0)+1);
let p=0;const na=a.length,nb=b.length;
while(p<na&&p<nb&&a[p]===b[p]&&ca.get(a[p])===1&&cb.get(a[p])===1)p++;
return p;
}
// Rule B: prefix while value does not appear later in a (a[p] not in a[p+1:]) and not in b[p+1:]
function ruleB(a,b){
const na=a.length,nb=b.length;let p=0;
while(p<na&&p<nb&&a[p]===b[p]){
const v=a[p];
// does v appear in a after p? or in b after p?
let later=false;
for(let k=p+1;k<na;k++)if(a[k]===v){later=true;break;}
if(!later)for(let k=p+1;k<nb;k++)if(b[k]===v){later=true;break;}
if(later)break; p++;
}
return p;
}
let badA=0,badB=0,total=0;
for(let t=0;t<200000;t++){
const n=Math.floor(Math.random()*8),m=Math.floor(Math.random()*8);
const al=3;
const a=Array.from({length:n},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
const b=Array.from({length:m},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
total++;const ref=canonicalDP(a,b);
const pa=ruleA(a,b);const ta=trimDiff(a,b,pa);if(!eq(ta,ref)){if(badA<5)console.log("A",JSON.stringify(a),JSON.stringify(b),"p=",pa);badA++;}
const pb=ruleB(a,b);const tb=trimDiff(a,b,pb);if(!eq(tb,ref)){if(badB<5)console.log("B",JSON.stringify(a),JSON.stringify(b),"p=",pb);badB++;}
}
console.log({total,badA,badB});
EOF
node /tmp/scratch/ref2.mjs{ total: 200000, badA: 0, badB: 0 }cat > /tmp/scratch/ref3.mjs <<'EOF'
// Rule B efficient + suffix trim; measure core size on realistic largely-identical inputs.
function lastIndexMap(arr){const m=new Map();for(let i=0;i<arr.length;i++)m.set(arr[i],i);return m;}
function coreSize(a,b){
const na=a.length,nb=b.length;
const lastA=lastIndexMap(a),lastB=lastIndexMap(b);
let p=0;while(p<na&&p<nb&&a[p]===b[p]&&lastA.get(a[p])===p&&lastB.get(b[p])===p)p++;
let s=0;while(s<na-p&&s<nb-p&&a[na-1-s]===b[nb-1-s])s++;
return {p,s,cn:na-p-s,cm:nb-p-s};
}
// Build a realistic file: distinct lines with occasional blank lines
function buildFile(n, blankEvery){
const out=[];
for(let i=0;i<n;i++){ out.push((blankEvery && i%blankEvery===0)?"":"line_"+i+"_content"); }
return out;
}
// revision: change a small block in middle
function revise(a, at, count){
const b=a.slice();
for(let k=0;k<count;k++) b[at+k]="CHANGED_"+k;
return b;
}
for(const blankEvery of [0, 50, 10, 3]){
const a=buildFile(100000, blankEvery);
const b=revise(a, 50000, 5);
const {p,s,cn,cm}=coreSize(a,b);
console.log("blankEvery="+blankEvery, "prefixTrim="+p, "suffixTrim="+s, "core="+cn+"x"+cm, "cells="+(cn*cm));
}
// change at very end and very start
{
const a=buildFile(100000, 10);
const b=a.slice(); b[5]="CHANGED";
console.log("earlyChange blankEvery10:", coreSize(a,b));
}
EOF
node /tmp/scratch/ref3.mjsblankEvery=0 prefixTrim=50000 suffixTrim=49995 core=5x5 cells=25
blankEvery=50 prefixTrim=0 suffixTrim=49995 core=50005x50005 cells=2500500025
blankEvery=10 prefixTrim=0 suffixTrim=49995 core=50005x50005 cells=2500500025
blankEvery=3 prefixTrim=0 suffixTrim=49995 core=50005x50005 cells=2500500025
earlyChange blankEvery10: { p: 0, s: 99994, cn: 6, cm: 6 }cat > /tmp/scratch/ref4.mjs <<'EOF'
function canonicalDP(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
// file with blanks every 5, 200 lines, change at 100
function buildFile(n,be){const out=[];for(let i=0;i<n;i++)out.push((i%be===0)?"":"L"+i);return out;}
const a=buildFile(60,5);
const b=a.slice(); b[30]="CHANGED";
const s=canonicalDP(a,b);
// print ops with positions, show first 40
let ai=0,bi=0,str=[];
for(const e of s){ str.push(e.op+":"+JSON.stringify(e.line)); }
console.log(str.slice(0,40).join(" "));
console.log("...");
console.log(str.slice(40).join(" "));
// count ops
const c={eq:0,del:0,ins:0};for(const e of s)c[e.op]++;
console.log(c);
EOF
node /tmp/scratch/ref4.mjseq:"" eq:"L1" eq:"L2" eq:"L3" eq:"L4" eq:"" eq:"L6" eq:"L7" eq:"L8" eq:"L9" eq:"" eq:"L11" eq:"L12" eq:"L13" eq:"L14" eq:"" eq:"L16" eq:"L17" eq:"L18" eq:"L19" eq:"" eq:"L21" eq:"L22" eq:"L23" eq:"L24" eq:"" eq:"L26" eq:"L27" eq:"L28" eq:"L29" del:"" ins:"CHANGED" eq:"L31" eq:"L32" eq:"L33" eq:"L34" eq:"" eq:"L36" eq:"L37" eq:"L38"
...
eq:"L39" eq:"" eq:"L41" eq:"L42" eq:"L43" eq:"L44" eq:"" eq:"L46" eq:"L47" eq:"L48" eq:"L49" eq:"" eq:"L51" eq:"L52" eq:"L53" eq:"L54" eq:"" eq:"L56" eq:"L57" eq:"L58" eq:"L59"
{ eq: 59, del: 1, ins: 1 }cat > /tmp/scratch/band.mjs <<'EOF'
function applyPatch(o,edits){const out=[];let i=0;for(const e of edits){if(e.op==="eq"){if(o[i]!==e.line)throw 0;out.push(o[i]);i++;}else if(e.op==="del"){if(o[i]!==e.line)throw 0;i++;}else out.push(e.line);}if(i!==o.length)throw 1;return out;}
// reference: suffix-LCS DP walk
function refL(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
// full E DP walk
function fullE(a,b){const na=a.length,nb=b.length,W=nb+1;const E=new Int32Array((na+1)*(nb+1));
for(let j=nb;j>=0;j--)E[na*W+j]=nb-j;
for(let i=na;i>=0;i--)E[i*W+nb]=na-i;
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){
if(a[i]===b[j])E[i*W+j]=E[(i+1)*W+j+1];
else{const d=E[(i+1)*W+j],s=E[i*W+j+1];E[i*W+j]=1+(d<=s?d:s);}}
const out=[];let i=0,j=0;while(i<na||j<nb){
if(i<na && E[i*W+j]===1+E[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}
else if(j<nb && E[i*W+j]===1+E[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}
else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
let bad=0,total=0,vf=0;
for(let t=0;t<300000;t++){
const n=Math.floor(Math.random()*9),m=Math.floor(Math.random()*9),al=3;
const a=Array.from({length:n},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
const b=Array.from({length:m},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
total++;const r=refL(a,b),f=fullE(a,b);
if(!eq(applyPatch(a,f),b)){vf++;continue;}
if(!eq(r,f)){if(bad<8)console.log("DIFF",JSON.stringify(a),JSON.stringify(b),"\n ref",r.map(e=>e.op+e.line).join(","),"\n fE ",f.map(e=>e.op+e.line).join(","));bad++;}
}
console.log({total,bad,vf});
EOF
node /tmp/scratch/band.mjs{ total: 300000, bad: 0, vf: 0 }cat > /tmp/scratch/band2.mjs <<'EOF'
const INF=0x3fffffff;
function refL(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function bandE(a,b){
const na=a.length,nb=b.length;
if(na===0)return b.map(l=>({op:"ins",line:l}));
if(nb===0)return a.map(l=>({op:"del",line:l}));
let h=1;
const maxh=na+nb;
while(true){
// storage: rows i=0..na, each width 2h+1, col = j-(i-h)
const width=2*h+1;
const store=new Int32Array((na+1)*width).fill(INF);
const idx=(i,j)=>{const c=j-(i-h);if(c<0||c>=width)return -1;return i*width+c;};
const get=(i,j)=>{if(i<0||i>na||j<0||j>nb)return INF;const k=i-j;if(k>h||k<-h)return INF;const id=idx(i,j);return id<0?INF:store[id];};
for(let i=na;i>=0;i--){
const jlo=Math.max(0,i-h), jhi=Math.min(nb,i+h);
for(let j=jhi;j>=jlo;j--){
let v;
if(i===na) v=nb-j;
else if(j===nb) v=na-i;
else if(a[i]===b[j]) v=get(i+1,j+1);
else { const d=get(i+1,j), s=get(i,j+1); v=1+(d<=s?d:s); }
const id=idx(i,j); if(id>=0) store[id]=v;
}
}
const e00=get(0,0);
if(e00<=h){
// walk
const out=[];let i=0,j=0;
while(i<na||j<nb){
const cur=get(i,j);
if(i<na && cur===1+get(i+1,j)){out.push({op:"del",line:a[i]});i++;}
else if(j<nb && cur===1+get(i,j+1)){out.push({op:"ins",line:b[j]});j++;}
else {out.push({op:"eq",line:a[i]});i++;j++;}
}
return out;
}
h*=2; if(h>maxh){h=maxh; // final pass guaranteed exact
// (loop will accept since e00<=h always when h>=na+nb)
}
if(h>2*maxh) throw new Error("band failed");
}
}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
let bad=0,total=0;
for(let t=0;t<300000;t++){
const n=Math.floor(Math.random()*9),m=Math.floor(Math.random()*9),al=3;
const a=Array.from({length:n},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
const b=Array.from({length:m},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
total++;const r=refL(a,b),f=bandE(a,b);
if(!eq(r,f)){if(bad<8)console.log("DIFF",JSON.stringify(a),JSON.stringify(b),"\n ref",r.map(e=>e.op+e.line).join(","),"\n bnd",f.map(e=>e.op+e.line).join(","));bad++;}
}
console.log({total,bad});
EOF
node /tmp/scratch/band2.mjs{ total: 300000, bad: 0 }cat >> /tmp/scratch/band2.mjs <<'EOF'
// larger random equality with bigger alphabet & longer
let bad2=0,tot2=0;
for(let t=0;t<3000;t++){
const n=Math.floor(Math.random()*60),m=Math.floor(Math.random()*60),al=2+Math.floor(Math.random()*6);
const a=Array.from({length:n},()=>"v"+Math.floor(Math.random()*al));
const b=Array.from({length:m},()=>"v"+Math.floor(Math.random()*al));
tot2++;const r=refL(a,b),f=bandE(a,b);
if(!eq(r,f)){if(bad2<8)console.log("DIFF2",JSON.stringify(a),JSON.stringify(b));bad2++;}
}
console.log({tot2,bad2});
// perf test
function buildFile(n,be){const out=[];for(let i=0;i<n;i++)out.push((be&&i%be===0)?"":"line_"+i);return out;}
for(const [be,desc] of [[0,"no blanks"],[5,"blanks every5"]]){
const a=buildFile(100000,be);
const b=a.slice(); for(let k=0;k<5;k++)b[50000+k]="CHANGED_"+k;
const t0=process.hrtime.bigint();
const r=bandE(a,b);
const t1=process.hrtime.bigint();
const c={eq:0,del:0,ins:0};for(const e of r)c[e.op]++;
console.log(desc,"ms="+Number(t1-t0)/1e6, c, "mem(rss MB)="+(process.memoryUsage().rss/1048576).toFixed(0));
}
// big change spread
{
const a=buildFile(100000,0);
const b=buildFile(100000,0);
for(let k=0;k<50;k++) b[k*1000]="X"+k; // 50 scattered changes
const t0=process.hrtime.bigint();const r=bandE(a,b);const t1=process.hrtime.bigint();
const c={eq:0,del:0,ins:0};for(const e of r)c[e.op]++;
console.log("scattered50", "ms="+Number(t1-t0)/1e6,c);
}
EOF
node --max-old-space-size=2048 /tmp/scratch/band2.mjs 2>&1 | tail -8{ total: 300000, bad: 0 }
{ tot2: 3000, bad2: 0 }
no blanks ms=190.376853 { eq: 99995, del: 5, ins: 5 } mem(rss MB)=74
blanks every5 ms=182.462653 { eq: 99995, del: 5, ins: 5 } mem(rss MB)=74
scattered50 ms=1342.190532 { eq: 99950, del: 50, ins: 50 }import type { Edit } from "./types.js";
/**
* Compute the canonical minimal line-level edit script transforming `a` into `b`.
*
* Return an ordered `Edit[]` that, replayed against `a` by `applyPatch`,
* reproduces `b`. An `eq` consumes one line from each side (the lines are
* equal); a `del` consumes one line from `a`; an `ins` consumes one line from
* `b`. (See `EditOp` in types.ts.) The script must satisfy ALL THREE of the
* following; each is checked independently and validity + minimality is NOT
* sufficient.
*
* 1. VALID , `applyPatch(a, diff(a, b))` deep-equals `b`. Equivalently the
* `eq`+`del` lines (in order) equal `a`, the `eq`+`ins` lines equal `b`, and
* every `eq` carries a line equal to the one it consumes on each side.
* 2. MINIMAL , fewest non-`eq` ops of any valid script. With `C(a,b)` = the
* maximum achievable number of `eq` ops (the LCS length), the script has
* exactly `C(a,b)` `eq` ops and `a.length + b.length - 2*C(a,b)` non-`eq` ops.
* 3. CANONICAL , among the (often many) valid minimal scripts, return THE one
* defined below; the same `(a,b)` always yields it.
*
* The canonical script (the crux): read it left to right as an interleaving of
* `a` and `b`, walking cursors `(i, j)` from the start , `del` advances `i`,
* `ins` advances `j`, `eq` advances both (and requires `a[i] === b[j]`). Call an
* op *length-preserving at `(i, j)`* if, after taking it, the script can still be
* completed from the new position into a valid script meeting the clause-2
* minimality bound. At every step take the highest-priority length-preserving
* choice under this fixed priority:
* (1) `del` of `a[i]` if length-preserving at `(i, j)`;
* (2) else `ins` of `b[j]` if length-preserving at `(i, j)`;
* (3) else `eq` of the shared line (this case forces `a[i] === b[j]`).
* When `i` is at the end of `a` only `ins` remains; when `j` is at the end of
* `b` only `del` remains; when both are at the end the script ends.
*
* ---
*
* Implementation notes.
*
* Reformulated via the suffix edit-distance `E(i, j)` = the minimal number of
* non-`eq` ops to turn `a[i:]` into `b[j:]`:
*
* E(i, j) = (a[i] === b[j]) ? E(i+1, j+1)
* : 1 + min(E(i+1, j), E(i, j+1))
*
* An op is length-preserving at `(i, j)` exactly when it keeps us on a shortest
* path to the end:
* - `del` iff E(i, j) === 1 + E(i+1, j)
* - `ins` iff E(i, j) === 1 + E(i, j+1)
* - `eq` (forced; here `a[i] === b[j]`) iff E(i, j) === E(i+1, j+1)
* So the canonical walk reads off `del`, else `ins`, else `eq`, by querying `E`.
*
* Memory must stay proportional to the input , never an `n*m` table on the large,
* largely-identical inputs the engine sees. Two reductions achieve that:
*
* - Trim the longest common suffix (always canonical-safe: the priority pushes
* deletions early, hence matches late, so a trailing common run is emitted as
* `eq` verbatim) and trim a leading common run up to the first line whose value
* recurs further along either side (canonical-safe: a line that never recurs
* cannot have its match deferred, so it must be `eq`). On two revisions of a
* file these collapse the shared regions, leaving only the changed core.
*
* - Compute `E` for the remaining core only inside a diagonal band `|i-j| <= h`
* (off-band treated as +infinity), widening `h` by doubling until the answer
* is provably exact (`E(0,0) <= h`). Any shortest path stays within `|i-j| <=
* E(0,0)`, so the band holds every optimal path and the walk is exact. This is
* `O(coreLen * h)` memory/time , proportional to the input on largely-identical
* pairs, where the band is narrow. A small core uses a plain full table.
*/
export function diff(a: string[], b: string[]): Edit[] {
const na = a.length;
const nb = b.length;
// --- Trim a leading common run that is guaranteed to be `eq` canonically. ---
// A common prefix line whose value never recurs later (on either side) cannot
// have its match deferred, so the canonical script must emit it as `eq`.
const lastInA = new Map<string, number>();
for (let i = 0; i < na; i++) lastInA.set(a[i] as string, i);
const lastInB = new Map<string, number>();
for (let j = 0; j < nb; j++) lastInB.set(b[j] as string, j);
let p = 0;
while (
p < na &&
p < nb &&
a[p] === b[p] &&
lastInA.get(a[p] as string) === p &&
lastInB.get(b[p] as string) === p
) {
p++;
}
// --- Trim the longest common suffix (always canonical-safe). ---
let s = 0;
while (s < na - p && s < nb - p && a[na - 1 - s] === b[nb - 1 - s]) s++;
const aLo = p;
const aHi = na - s; // exclusive
const bLo = p;
const bHi = nb - s; // exclusive
const cn = aHi - aLo;
const cm = bHi - bLo;
const out: Edit[] = [];
// Leading common run -> `eq`.
for (let k = 0; k < p; k++) out.push({ op: "eq", line: a[k] as string });
// Differing core.
if (cn === 0) {
for (let j = bLo; j < bHi; j++) out.push({ op: "ins", line: b[j] as string });
} else if (cm === 0) {
for (let i = aLo; i < aHi; i++) out.push({ op: "del", line: a[i] as string });
} else if ((cn + 1) * (cm + 1) <= FULL_TABLE_CELL_LIMIT) {
diffCoreFull(a, b, aLo, aHi, bLo, bHi, out);
} else {
diffCoreBanded(a, b, aLo, aHi, bLo, bHi, out);
}
// Trailing common suffix -> `eq`.
for (let k = na - s; k < na; k++) out.push({ op: "eq", line: a[k] as string });
return out;
}
/** Cells in a full DP table we are willing to allocate before switching to a band. */
const FULL_TABLE_CELL_LIMIT = 16_000_000;
/**
* Canonical walk over the core `a[aLo:aHi]` vs `b[bLo:bHi]` using a full suffix-LCS
* table. `L(i, j)` is the LCS length of the corresponding core suffixes; del/ins are
* length-preserving iff they leave `L` unchanged.
*/
function diffCoreFull(
a: string[],
b: string[],
aLo: number,
aHi: number,
bLo: number,
bHi: number,
out: Edit[],
): void {
const cn = aHi - aLo;
const cm = bHi - bLo;
const w = cm + 1;
const L = new Int32Array((cn + 1) * w);
for (let i = cn - 1; i >= 0; i--) {
const ai = a[aLo + i] as string;
const rowi = i * w;
const rown = (i + 1) * w;
for (let j = cm - 1; j >= 0; j--) {
if (ai === (b[bLo + j] as string)) {
L[rowi + j] = L[rown + (j + 1)] + 1;
} else {
const d = L[rown + j];
const e = L[rowi + (j + 1)];
L[rowi + j] = d >= e ? d : e;
}
}
}
let i = 0;
let j = 0;
while (i < cn || j < cm) {
const cur = L[i * w + j];
if (i < cn && cur === L[(i + 1) * w + j]) {
out.push({ op: "del", line: a[aLo + i] as string });
i++;
} else if (j < cm && cur === L[i * w + (j + 1)]) {
out.push({ op: "ins", line: b[bLo + j] as string });
j++;
} else {
out.push({ op: "eq", line: a[aLo + i] as string });
i++;
j++;
}
}
}
/**
* Canonical walk over the core using the suffix edit-distance `E`, computed only
* within a diagonal band `|i-j| <= h` (off-band = +infinity), with `h` doubled until
* the result is provably exact. Memory/time `O(coreLen * h)`.
*/
function diffCoreBanded(
a: string[],
b: string[],
aLo: number,
aHi: number,
bLo: number,
bHi: number,
out: Edit[],
): void {
const cn = aHi - aLo;
const cm = bHi - bLo;
const INF = 0x3fffffff;
const maxH = cn + cm; // band this wide is the full table -> always exact
let h = 1;
// eslint-disable-next-line no-constant-condition
for (;;) {
if (h > maxH) h = maxH;
const width = 2 * h + 1;
const store = new Int32Array((cn + 1) * width);
store.fill(INF);
// E for core indices i in [0,cn], j in [0,cm]; column = j - (i - h).
const get = (i: number, j: number): number => {
if (i < 0 || i > cn || j < 0 || j > cm) return INF;
const k = i - j;
if (k > h || k < -h) return INF;
return store[i * width + (j - (i - h))];
};
for (let i = cn; i >= 0; i--) {
const base = i * width;
const jLo = Math.max(0, i - h);
const jHi = Math.min(cm, i + h);
const ai = i < cn ? (a[aLo + i] as string) : "";
for (let j = jHi; j >= jLo; j--) {
let v: number;
if (i === cn) {
v = cm - j;
} else if (j === cm) {
v = cn - i;
} else if (ai === (b[bLo + j] as string)) {
v = get(i + 1, j + 1);
} else {
const d = get(i + 1, j);
const e = get(i, j + 1);
v = 1 + (d <= e ? d : e);
}
store[base + (j - (i - h))] = v;
}
}
if (get(0, 0) <= h) {
let i = 0;
let j = 0;
while (i < cn || j < cm) {
const cur = get(i, j);
if (i < cn && cur === 1 + get(i + 1, j)) {
out.push({ op: "del", line: a[aLo + i] as string });
i++;
} else if (j < cm && cur === 1 + get(i, j + 1)) {
out.push({ op: "ins", line: b[bLo + j] as string });
j++;
} else {
out.push({ op: "eq", line: a[aLo + i] as string });
i++;
j++;
}
}
return;
}
h *= 2;
}
}
The file /home/user/app/src/diff/myers.ts has been updated successfully. (file state is current in your context , no need to Read it back)
npm run typecheck 2>&1 | tail -20
> diff-patch-engine@0.2.0 typecheck > tsc -p tsconfig.json --noEmit
npm run build >/dev/null 2>&1 && cat > /tmp/scratch/verify.mjs <<'EOF'
import { diff } from "/home/user/app/dist/diff/myers.js";
import { applyPatch } from "/home/user/app/dist/diff/patch.js";
function refL(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
let bad=0,vf=0,total=0;
// alphabet 3 small
for(let t=0;t<400000;t++){
const n=Math.floor(Math.random()*9),m=Math.floor(Math.random()*9),al=2+Math.floor(Math.random()*3);
const a=Array.from({length:n},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
const b=Array.from({length:m},()=>String.fromCharCode(97+Math.floor(Math.random()*al)));
total++;const r=refL(a,b),f=diff(a,b);
if(!eq(applyPatch(a,f),b)){vf++;if(vf<5)console.log("INVALID",JSON.stringify(a),JSON.stringify(b));continue;}
if(!eq(r,f)){if(bad<10)console.log("DIFF",JSON.stringify(a),JSON.stringify(b),"\n ref",r.map(e=>e.op+e.line).join(","),"\n got",f.map(e=>e.op+e.line).join(","));bad++;}
}
console.log("small alpha:",{total,vf,bad});
EOF
node /tmp/scratch/verify.mjsExit code 1
node:internal/errors:497
ErrorCaptureStackTrace(err);
^
Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/home/user/app/dist/diff/myers.js' imported from /tmp/scratch/verify.mjs
at new NodeError (node:internal/errors:406:5)
at finalizeResolution (node:internal/modules/esm/resolve:233:11)
at moduleResolve (node:internal/modules/esm/resolve:845:10)
at defaultResolve (node:internal/modules/esm/resolve:1043:11)
at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:383:12)
at ModuleLoader.resolve (node:internal/modules/esm/loader:352:25)
at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:228:38)
at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:85:39)
at link (node:internal/modules/esm/module_job:84:36) {
url: 'file:///home/user/app/dist/diff/myers.js',
code: 'ERR_MODULE_NOT_FOUND'
}
Node.js v20.9.0npm run build 2>&1 | tail -20; echo "---"; ls dist 2>/dev/null; ls dist/diff 2>/dev/null
Exit code 2 > diff-patch-engine@0.2.0 build > tsc -p tsconfig.json --- src test
npx tsc -p tsconfig.json 2>&1 | head -20; echo "EXIT"; find dist -name "*.js" 2>/dev/null | head
EXIT dist/src/index.js dist/test/patch.test.js dist/src/diff/types.js dist/src/diff/myers.js dist/src/diff/errors.js dist/src/diff/patch.js dist/src/diff/text.js
cd /tmp/scratch && sed -i 's#/dist/diff/#/dist/src/diff/#g' verify.mjs && node verify.mjs
small alpha: { total: 400000, vf: 0, bad: 0 }
Shell cwd was reset to /home/user/appcat > /tmp/scratch/verify2.mjs <<'EOF'
import { diff } from "/home/user/app/dist/src/diff/myers.js";
import { applyPatch } from "/home/user/app/dist/src/diff/patch.js";
function refL(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
function check(a,b,label){const r=refL(a,b),f=diff(a,b);
if(!eq(applyPatch(a,f),b)){console.log("INVALID",label);return false;}
if(!eq(r,f)){console.log("MISMATCH",label,"\n a",JSON.stringify(a),"\n b",JSON.stringify(b),"\n ref",r.map(e=>e.op+e.line).join(","),"\n got",f.map(e=>e.op+e.line).join(","));return false;}
return true;}
// medium/large alphabet & longer, force full+band paths via FULL_TABLE_CELL_LIMIT? small here uses full. Add longer to hit band rarely.
let bad=0,total=0;
for(let t=0;t<20000;t++){
const n=Math.floor(Math.random()*120),m=Math.floor(Math.random()*120),al=1+Math.floor(Math.random()*10);
const a=Array.from({length:n},()=>"x"+Math.floor(Math.random()*al));
const b=Array.from({length:m},()=>"x"+Math.floor(Math.random()*al));
total++; if(!check(a,b,"rand"+t)) {bad++; if(bad>5)break;}
}
console.log("varied:",{total,bad});
// edge cases
const E=[];
console.log("equal:", eq(diff(["a","b"],["a","b"]), [{op:"eq",line:"a"},{op:"eq",line:"b"}]));
console.log("aEmpty:", eq(diff([],["x","y"]), [{op:"ins",line:"x"},{op:"ins",line:"y"}]));
console.log("bEmpty:", eq(diff(["x","y"],[]), [{op:"del",line:"x"},{op:"del",line:"y"}]));
console.log("bothEmpty:", eq(diff([],[]), []));
console.log("emptyStr:", eq(applyPatch([""],diff([""],[""])),[""]));
console.log("dupBoundary xx->x:", diff(["x","x"],["x"]).map(e=>e.op+e.line).join(","));
console.log("opnames:", check(["del","ins","eq"],["eq","del"],"opnames"));
console.log("ws/emoji:", check([" ","\t","😀","a"],["😀"," ","a","\t"],"ws"));
EOF
node /tmp/scratch/verify2.mjsvaried: { total: 20000, bad: 0 }
equal: true
aEmpty: true
bEmpty: true
bothEmpty: true
emptyStr: true
dupBoundary xx->x: delx,eqx
opnames: true
ws/emoji: truecat > /tmp/scratch/verify3.mjs <<'EOF'
import { diff } from "/home/user/app/dist/src/diff/myers.js";
import { applyPatch } from "/home/user/app/dist/src/diff/patch.js";
function refL(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function eq(x,y){return JSON.stringify(x)===JSON.stringify(y);}
// Force band path: core ~4500x4500 with no trimmable prefix/suffix, moderate alphabet so D large-ish but < band cap memory
for(const al of [50, 8, 4500]){
const n=4500,m=4500;
const a=Array.from({length:n},(_,i)=>"u"+(i)+"_"+Math.floor(Math.random()*al));
// make b a perturbation; ensure first & last differ to avoid trims
const b=a.slice();
for(let k=0;k<300;k++){ const pos=Math.floor(Math.random()*m); b[pos]="V"+pos+"_"+Math.floor(Math.random()*al);}
b[0]="DIFF_START"; b[m-1]="DIFF_END"; a[0]="diff_start"; a[n-1]="diff_end";
const t0=process.hrtime.bigint();
const f=diff(a,b); const t1=process.hrtime.bigint();
const r=refL(a,b);
console.log("band core al="+al, "valid="+eq(applyPatch(a,f),b), "match="+eq(r,f), "ms="+(Number(t1-t0)/1e6).toFixed(0));
}
EOF
node --max-old-space-size=3072 /tmp/scratch/verify3.mjsband core al=50 valid=true match=true ms=394 band core al=8 valid=true match=true ms=385 band core al=4500 valid=true match=true ms=406
cat > /tmp/scratch/perf.mjs <<'EOF'
import { diff } from "/home/user/app/dist/src/diff/myers.js";
import { applyPatch } from "/home/user/app/dist/src/diff/patch.js";
function buildFile(n,be){const out=[];for(let i=0;i<n;i++)out.push((be&&i%be===0)?"":"line_"+i+"_xyz");return out;}
function run(label,a,b){
const t0=process.hrtime.bigint();const f=diff(a,b);const t1=process.hrtime.bigint();
const ok=JSON.stringify(applyPatch(a,f))===JSON.stringify(b);
const c={eq:0,del:0,ins:0};for(const e of f)c[e.op]++;
console.log(label.padEnd(32),"valid="+ok,"ms="+(Number(t1-t0)/1e6).toFixed(0).padStart(5),"rssMB="+(process.memoryUsage().rss/1048576).toFixed(0),JSON.stringify(c));
}
// 1) tiny change middle, distinct lines
{const a=buildFile(100000,0);const b=a.slice();for(let k=0;k<5;k++)b[50000+k]="CH"+k;run("distinct, 5-line change",a,b);}
// 2) blanks every 5 (defeat prefix rule), small change
{const a=buildFile(100000,5);const b=a.slice();for(let k=0;k<5;k++)b[50000+k]="CH"+k;run("blanks/5, 5-line change",a,b);}
// 3) large contiguous change (1000 lines) distinct
{const a=buildFile(100000,0);const b=a.slice();for(let k=0;k<1000;k++)b[40000+k]="CH"+k;run("distinct, 1000-line change",a,b);}
// 4) large contiguous change, blanks/5 (large core + moderate D)
{const a=buildFile(100000,5);const b=a.slice();for(let k=0;k<1000;k++)b[40000+k]="CH"+k;run("blanks/5, 1000-line change",a,b);}
// 5) change at start
{const a=buildFile(100000,0);const b=a.slice();for(let k=0;k<5;k++)b[k]="CH"+k;run("distinct, change at start",a,b);}
// 6) change at end
{const a=buildFile(100000,0);const b=a.slice();for(let k=0;k<5;k++)b[99990+k]="CH"+k;run("distinct, change at end",a,b);}
// 7) pure insertion of big block
{const a=buildFile(60000,0);const b=a.slice(0,30000).concat(buildFile(40000,0).map(x=>x+"_NEW"),a.slice(30000));run("insert 40k block",a,b);}
// 8) completely different (worst case-ish, but small to keep ref-free) - just timing
{const a=buildFile(2000,0);const b=buildFile(2000,0).map(x=>x+"_b");run("fully different 2k",a,b);}
// 9) equal large
{const a=buildFile(100000,0);run("equal 100k",a,a.slice());}
EOF
node --max-old-space-size=4096 /tmp/scratch/perf.mjsExit code 137
distinct, 5-line change valid=true ms= 61 rssMB=68 {"eq":99995,"del":5,"ins":5}
blanks/5, 5-line change valid=true ms= 145 rssMB=113 {"eq":99995,"del":5,"ins":5}
distinct, 1000-line change valid=true ms= 50 rssMB=103 {"eq":99000,"del":1000,"ins":1000}
/bin/bash: line 59: 1769 Killed node --max-old-space-size=4096 /tmp/scratch/perf.mjscat > /tmp/scratch/shift.mjs <<'EOF'
function refL(a,b){const na=a.length,nb=b.length,W=nb+1;const L=new Int32Array((na+1)*(nb+1));
for(let i=na-1;i>=0;i--)for(let j=nb-1;j>=0;j--){if(a[i]===b[j])L[i*W+j]=L[(i+1)*W+j+1]+1;else{const d=L[(i+1)*W+j],s=L[i*W+j+1];L[i*W+j]=d>=s?d:s;}}
const out=[];let i=0,j=0;while(i<na||j<nb){if(i<na&&L[i*W+j]===L[(i+1)*W+j]){out.push({op:"del",line:a[i]});i++;}else if(j<nb&&L[i*W+j]===L[i*W+j+1]){out.push({op:"ins",line:b[j]});j++;}else{out.push({op:"eq",line:a[i]});i++;j++;}}return out;}
function buildFile(n,be){const out=[];for(let i=0;i<n;i++)out.push((be&&i%be===0)?"":"line_"+i);return out;}
// blanks every 5, change replacing lines 100..119
const a=buildFile(200,5);
const b=a.slice(); for(let k=0;k<20;k++) b[100+k]="CH"+k;
const s=refL(a,b);
// find first non-eq op position (in a index)
let ai=0; let firstNonEq=-1, lastNonEq=-1, idx=0;
for(const e of s){ if(e.op!=="eq"){ if(firstNonEq<0)firstNonEq=idx; lastNonEq=idx;} idx++; if(e.op!=="ins")ai++; }
// show ops around first non-eq with a-index
let aii=0; const view=[];
idx=0;
for(const e of s){ const tag=(e.op==="ins")?("ins@-"):(e.op+"@"+aii); view.push(tag); if(e.op!=="ins")aii++; idx++; }
console.log("first non-eq op index:",firstNonEq,"last:",lastNonEq,"total ops:",s.length);
console.log("ops",firstNonEq-3,"..",lastNonEq+3,":");
console.log(view.slice(Math.max(0,firstNonEq-3),lastNonEq+4).join(" "));
EOF
node /tmp/scratch/shift.mjsfirst non-eq op index: 100 last: 139 total ops: 220 ops 97 .. 142 : eq@97 eq@98 eq@99 del@100 del@101 del@102 del@103 del@104 del@105 del@106 del@107 del@108 del@109 del@110 del@111 del@112 del@113 del@114 del@115 del@116 del@117 del@118 del@119 ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- ins@- eq@120 eq@121 eq@122
No file changes, the agent left the workspace untouched.
=== running test suite in /home/user/app ===
RUN v1.6.0 /home/user/app
✓ test/diff.test.ts > diff > canonical edit scripts (pinned by the del-before-ins tie-break) > replace in the middle
✓ test/diff.test.ts > diff > canonical edit scripts (pinned by the del-before-ins tie-break) > a transposition keeps the LATER match and deletes the earlier line
✓ test/diff.test.ts > diff > canonical edit scripts (pinned by the del-before-ins tie-break) > duplicate runs align to the LAST surviving equal lines
✓ test/diff.test.ts > diff > canonical edit scripts (pinned by the del-before-ins tie-break) > interleaved unique deletions collapse to eq/del pairs
✓ test/diff.test.ts > diff > canonical edit scripts (pinned by the del-before-ins tie-break) > classic ABCABBA / CBABAC example resolves to the canonical script
✓ test/diff.test.ts > diff > round-trips through applyPatch on realistic text > patches a small source edit
✓ test/diff.test.ts > diff > round-trips through applyPatch on realistic text > preserves a trailing newline through split/diff/apply/join
✓ test/diff.test.ts > diff > canonical script , exhaustive over small inputs > matches the independent canonical oracle for every 2-letter pair up to length 5
✓ test/diff.test.ts > diff > canonical script , exhaustive over small inputs > matches the independent canonical oracle for every 3-letter pair up to length 4
✓ test/diff.test.ts > diff > adversarial: randomized exact-canonical differential > matches the canonical oracle across many longer, duplicate-heavy pairs
✓ test/diff.test.ts > diff > adversarial: randomized exact-canonical differential > matches the canonical oracle on a binary alphabet (maximal ambiguity)
✓ test/diff.test.ts > diff > adversarial: randomized exact-canonical differential > scales to a larger near-identical pair (single-line change)
✓ test/diff.test.ts > diff > performance: must stay within O(n*m) and produce the canonical script > diffs a 1500x1500 low-overlap pair well under the timeout
✓ test/diff.test.ts > diff > performance: must stay within O(n*m) and produce the canonical script > produces the canonical script on a 2000x2000 block-edit pair
✓ test/diff.test.ts > diff > tie-break orientation , extra hand-pinned litmus cases > reverse transposition still keeps the LATER match (del earlier copy first)
✓ test/diff.test.ts > diff > tie-break orientation , extra hand-pinned litmus cases > 3-cycle rotation resolves to the canonical del-before-ins script
✓ test/diff.test.ts > diff > tie-break orientation , extra hand-pinned litmus cases > a duplicated line that is removed keeps the LAST surviving copy
✓ test/diff.test.ts > diff > tie-break orientation , extra hand-pinned litmus cases > growing a run of duplicates inserts at the canonical position
✓ test/diff.test.ts > diff > tie-break orientation , extra hand-pinned litmus cases > symmetry is NOT assumed: diff(a,b) and diff(b,a) are independently canonical
✓ test/diff.test.ts > diff > adversarial edge cases > no common subsequence at all -> all del then all ins, in that order
✓ test/diff.test.ts > diff > adversarial edge cases > single-element equal / unequal
✓ test/diff.test.ts > diff > adversarial edge cases > very long common prefix with a single trailing change
✓ test/diff.test.ts > diff > adversarial edge cases > very long common suffix with a single leading change
✓ test/diff.test.ts > diff > adversarial edge cases > an all-identical block shrinks by deleting the surplus from the LEFT
✓ test/diff.test.ts > diff > adversarial edge cases > unicode, emoji, and whitespace-only lines compare by exact string equality
✓ test/diff.test.ts > diff > adversarial edge cases > lines that look like edit ops or contain newlines are treated opaquely
✓ test/diff.test.ts > diff > adversarial edge cases > combining-character vs precomposed forms are NOT equal (no normalization)
✓ test/diff.test.ts > diff > canonical script , WIDER exhaustive sweeps (cross-checked oracles) > matches both canonical oracles for every 2-letter pair up to length 6 1315ms
✓ test/diff.test.ts > diff > canonical script , WIDER exhaustive sweeps (cross-checked oracles) > matches both canonical oracles for every 3-letter pair up to length 5 5612ms
✓ test/diff.test.ts > diff > adversarial: LARGER randomized exact-canonical differential > matches both oracles across thousands of long, duplicate-heavy pairs 676ms
✓ test/diff.test.ts > diff > adversarial: LARGER randomized exact-canonical differential > stays canonical with realistic line strings and block moves
✓ test/diff.test.ts > diff > performance: an inefficient or super-quadratic approach times out > diffs a 2200x2200 low-overlap pair within a tight timeout
✓ test/diff.test.ts > diff > performance: an inefficient or super-quadratic approach times out > diffs a 3000x3000 block-edit pair within a tight timeout 306ms
✓ test/diff.test.ts > diff > canonical script , WIDEST exhaustive sweep (binary, length <= 7) > matches both canonical oracles for every 2-letter pair up to length 7 5049ms
✓ test/diff.test.ts > diff > deep tie-break chains , del-before-ins must hold across long runs > all-distinct replacement block: every del precedes every ins
✓ test/diff.test.ts > diff > deep tie-break chains , del-before-ins must hold across long runs > alternating shared/unique forces del-before-ins at each junction
✓ test/diff.test.ts > diff > deep tie-break chains , del-before-ins must hold across long runs > deletion defers to insertion exactly when deleting would break minimality
✓ test/diff.test.ts > diff > latest-anchor under heavy duplication , the later copy survives > shrinking a duplicate run deletes the LEFT surplus
✓ test/diff.test.ts > diff > latest-anchor under heavy duplication , the later copy survives > growing a duplicate run inserts BEFORE the surviving (later) anchor
✓ test/diff.test.ts > diff > latest-anchor under heavy duplication , the later copy survives > interleaved duplicates keep each latest viable anchor
✓ test/diff.test.ts > diff > latest-anchor under heavy duplication , the later copy survives > two distinct repeated lines interleaved keep their own latest anchors
✓ test/diff.test.ts > diff > adversarial: SECOND larger randomized exact-canonical differential > matches both oracles across many short-alphabet, duplicate-saturated pairs 873ms
✓ test/diff.test.ts > diff > memory: large mostly-identical inputs must not build an n*m table > change at the START (long common suffix)
✓ test/diff.test.ts > diff > memory: large mostly-identical inputs must not build an n*m table > change at the END (long common prefix)
✓ test/diff.test.ts > diff > memory: large mostly-identical inputs must not build an n*m table > change in the MIDDLE (long common prefix AND suffix)
✓ test/diff.test.ts > diff > memory: large mostly-identical inputs must not build an n*m table > identical huge inputs -> all eq
✓ test/diff.test.ts > diff > more edge cases (added) > op-name strings ('eq'/'del'/'ins') as line content are opaque
✓ test/diff.test.ts > diff > more edge cases (added) > empty-string lines interspersed
✓ test/diff.test.ts > diff > more edge cases (added) > whitespace-only lines that differ by kind
✓ test/diff.test.ts > diff > more edge cases (added) > lines containing embedded newlines are single opaque values
✓ test/diff.test.ts > diff > more edge cases (added) > unicode: combining vs precomposed are distinct (no normalization)
✓ test/diff.test.ts > diff > more edge cases (added) > emoji ZWJ sequences are opaque strings
✓ test/diff.test.ts > diff > more edge cases (added) > b is the reverse of a
✓ test/diff.test.ts > diff > more edge cases (added) > difference is only trailing whitespace
✓ test/diff.test.ts > diff > more edge cases (added) > repeated block pattern, cyclically shifted
✓ test/diff.test.ts > diff > more edge cases (added) > long run of one value with a single mid insertion (latest anchor)
✓ test/diff.test.ts > diff > more edge cases (added) > JSON-looking duplicate lines align by latest anchor
✓ test/diff.test.ts > diff > more edge cases (added) > medium near-identical: one line changed among 60
× test/diff.test.ts > diff > large un-peelable cores: sub-quadratic memory AND exact canonical > disjoint halves bridged by a shared duplicate comb 2547ms
→ Array buffer allocation failed
✓ test/diff.test.ts > diff > large un-peelable cores: sub-quadratic memory AND exact canonical > alternating (p,q) vs (q,p) at scale
✓ test/diff.test.ts > diff > large un-peelable cores: sub-quadratic memory AND exact canonical > peelable unique affixes around a large duplicate mid-core
✓ test/diff.test.ts > diff > more hardening edge cases (added) > highly skewed sizes: one line vs a large block, single match
✓ test/diff.test.ts > diff > more hardening edge cases (added) > trailing newline (final empty entry) is matched as eq at scale
✓ test/diff.test.ts > diff > more hardening edge cases (added) > deep alternating shared/unique tie-break chain at scale
✓ test/diff.test.ts > diff > large ambiguous duplicate-heavy cores match the canonical script > linear-space oracle agrees with the n*m oracle on every 2-letter pair up to length 6 359ms
× test/diff.test.ts > diff > large ambiguous duplicate-heavy cores match the canonical script > diff matches the linear-space canonical oracle on large random small-alphabet pairs 3269ms
→ Array buffer allocation failed
✓ test/patch.test.ts > applyPatch (provided) > replays eq/del/ins to reconstruct the target
✓ test/patch.test.ts > applyPatch (provided) > throws trailing_lines when the script leaves original lines unconsumed
⎯⎯⎯⎯⎯⎯⎯ Failed Tests 2 ⎯⎯⎯⎯⎯⎯⎯
FAIL test/diff.test.ts > diff > large un-peelable cores: sub-quadratic memory AND exact canonical > disjoint halves bridged by a shared duplicate comb
RangeError: Array buffer allocation failed
❯ diffCoreBanded src/diff/myers.ts:204:19
202| if (h > maxH) h = maxH;
203| const width = 2 * h + 1;
204| const store = new Int32Array((cn + 1) * width);
| ^
205| store.fill(INF);
206|
❯ Module.diff src/diff/myers.ts:116:5
❯ test/diff.test.ts:1209:21
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[1/2]⎯
FAIL test/diff.test.ts > diff > large ambiguous duplicate-heavy cores match the canonical script > diff matches the linear-space canonical oracle on large random small-alphabet pairs
RangeError: Array buffer allocation failed
❯ diffCoreBanded src/diff/myers.ts:204:19
202| if (h > maxH) h = maxH;
203| const width = 2 * h + 1;
204| const store = new Int32Array((cn + 1) * width);
| ^
205| store.fill(INF);
206|
❯ Module.diff src/diff/myers.ts:116:5
❯ test/diff.test.ts:1350:25
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯[2/2]⎯
Test Files 1 failed | 1 passed (2)
Tests 2 failed | 66 passed (68)
Start at 13:32:40
Duration 22.99s (transform 258ms, setup 0ms, collect 279ms, tests 22.17s, environment 0ms, prepare 178ms)
=== vitest exit status: 1 ===
RESULT: FAIL (reward=0)Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_616fbc80cf92449f. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.
Trial trial_616fbc80cf92449f · verifier authoritative; classifier explanatory.