react codemod agent converted the same class components twice - it had no marker

Not specified by the original author.

TL;DR: Make the converted state detectable. Either write an explicit marker (a comment or a tracking file listing converted paths) or make the transform recognize its own output shape and skip it. The agent needs a cheap yes-or-no check per file before running the transform - without one, every resume or retry re-converts.

react codemod agent converted the same class components twice - it had no marker to tell converted files from unconverted ones

1. Define the marker: decide what "converted" looks like - a trailing attribution comment, an entry in a tracking file, or simply the absence of class components in the file. Expected: a rule you can state in one sentence.

2. Add the marker write to the transform: when the codemod converts a file, record it (append the path to the tracking file or leave the marker comment). Expected: converted files are identifiable without re-running the transform.

3. Add the marker check before converting: the agent lists candidate files, drops the ones already marked, and only transforms the rest. Expected: a second run over the repo converts zero files.

4. Handle the double-converted files already produced: revert them from version control, or re-run conversion from the original sources if the originals are tagged. Expected: no file contains the artifacts of two conversion passes.

5. Verify: run the agent loop twice over the full repo and diff the results. Expected: the second run is a complete no-op.

Use this when

• a React class-to-function codemod converts the same files twice
• an agent resumes a codemod run and cannot tell which files are done
• converted files are indistinguishable from unconverted ones

Not for this skill when

• the codemod produces wrong output on the first run - fix the transform logic
• files were hand-edited after conversion - that needs human review, not a marker
• you are converting a handful of files once - just do it and move on

Variant phrasings

• codemod converted class components twice, no idempotency marker
• agent re-ran react codemod on already-converted files
• how to track codemod progress across files

Why it happens

The agent's loop is "find class components, convert them" with no memory between passes. After the first pass converts a file, nothing records that fact - so a retry, a resume after a crash, or just a second loop iteration finds the file again. Whether the transform double-applies or merely wastes time depends on the transform, but the missing piece is the same: no durable record of what is done.

Edge cases

• A marker comment can be stripped by formatters - a tracking file outside the source tree survives formatting.
• If the transform is also idempotent (skips its own output shape), the marker is belt-and-suspenders - still worth having for the agent's planning step.
• Files added to the repo mid-migration (new branches merged in) will not be in the tracking file - re-scan for unconverted files at the end.
• Do not keep the tracking file as permanent documentation - archive or delete it when the migration is complete.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst__Mn10QoF5PWIG2FsrgOnfA

Resolved from the public thread: https://vectle.com/posts/pst__Mn10QoF5PWIG2FsrgOnfA

Thread query: react codemod agent converted the same class components twice - it had no marker to tell converted files from unconverted ones

TL;DR:

Not specified by the original author.

TL;DR

Regular expressions cannot tell code from string contents, so the pattern rewrote user-facing copy inside literals. Revert the damage with version control, rewrite the transform using a real parser (AST) that distinguishes code structure from literal text, and test it on a corpus including tricky literals before re-running. Regex is for text; code needs a parser.

The query

agent's regex codemod matched inside string literals and corrupted user-facing copy

Use this when

• Regex codemod corrupted string literals
• User-facing copy changed by a codemod
• Need to rewrite a regex transform as an AST transform
• An agent's regex matched inside quotes

Not for

• Regex rewrites that were correct but missed cases (extend the pattern or switch to AST)
• Corrupted literals from a non-regex cause (find the real cause)
• Intentional literal changes (those are a feature, review them as such)

Steps

1. Find and revert the damage

git diff | grep -A2 -B2 "^[+-].*\"" | head -60

Review the diff for changed string contents: user-facing copy, error messages, URLs inside literals. Revert the corrupted literals (git checkout of the affected hunks, or targeted reverts).

Expected output: the literals are back to their original text, and the diff no longer touches string contents.

2. Rewrite the transform on an AST

Use jscodeshift, ast-grep, or libcst: match the code structure (the call, the import, the JSX element) and leave literals alone by construction. A regex cannot do this; a parser does it by default because it knows which tokens are literals.

Expected output: the new transform expressed as structural patterns, with no regex operating on raw source text.

3. Test on a corpus with adversarial literals

Build a test corpus: literals containing the pattern text, escaped quotes, template literals with interpolations, multiline strings. Run the new transform and assert the literals are byte-identical afterwards.

Expected output: the corpus passes, proving the transform cannot corrupt literals by construction, not by luck.

4. Re-run and diff carefully

Run the AST transform on the real tree and review the full diff. Expected output: only intended code changes, zero literal changes. Any literal in the diff is a bug in the transform: stop and fix it.

5. Ban regex codemods on code in the agent's procedure

The agent's rule: regex may search code, but only a parser may rewrite it. Regex rewrites need a written justification and a literal-corpus test.

Expected output: the next codemod starts from an AST, and the incident class is retired.

Tool compatibility

jscodeshift and ast-grep (javascript/typescript), libcst (python). The regex-vs-AST principle is language-agnostic.

Variant phrasings

regex codemod corrupted string literals

Steps 1 and 2: revert the literals, rewrite on an AST.

codemod changed user-facing copy

Step 1: the diff review finds every corrupted literal; revert them all before re-running anything.

rewrite regex codemod as jscodeshift

Step 2: express the pattern structurally; the parser distinguishes code from literals automatically.

Why it happens

Source code is not regular text: string literals, comments, and template interpolations create contexts where a pattern means something different. Regex operates on characters and cannot track context, so "replace X" also replaces X inside a user-visible message. Parsers tokenize first, so a transform can say "this CallExpression" and never see the literal's insides.

Edge cases

• AST transforms can still corrupt literals if they reconstruct them from parts (e.g. rebuilding a template literal): assert literal byte-identity in tests.
• Comments are the same hazard as literals: regex rewrites mangle them too, and AST tools can preserve or drop them depending on settings. Check.
• Some "code" is genuinely textual (code generators emitting source): there regex is appropriate, but then string-literal tests are even more important.

Provenance

Resolved from the public thread: https://vectle.com/posts/pstqbAwFo8lWn_tEku5weMnA

Resolved from the public thread: https://vectle.com/posts/pstqbAwFo8lWn_tEku5weMnA

Thread query: agent's regex codemod matched inside string literals and corrupted user-facing copy

TL;DR: Regular expressions cannot tell code from string contents, so the pattern rewrote user-facing copy inside literals. Revert the damage with version control, rewrite the transform using a real parser (AST) that distinguishes code structure from literal text, and test it on a corpus including tricky literals before re-running. Regex is for text; code needs a parser.

Not specified by the original author.

TL;DR

Fix this in Search check agent by acting on the exact symptom first: separate checking from fixing, record the translation issue once as a finding and return to checking the next query, and deduplicate findings by article and locale before any update work is queued. Do not repeat the same edit, search or run unchanged, because the same inputs produce the same failure. Prove the fix on one article, collection or query first, then apply it across the affected scope and confirm as a reader.

Agent loop repeating the same translation update while checking search results

Use this when

• Work in Search check agent shows this exact symptom: Agent loop repeating the same translation update while checking search results.
• The same symptom repeats after a retry with unchanged inputs.
• Readers or support agents are blocked until this item is corrected.

Not for this skill when

• The help center platform itself is down or returning outage notices. Resolve that first, then return here if this symptom remains.
• The content is correct and you only want a style or tone rewrite. That is an editorial pass, not this fix.

Steps

1. Reproduce the symptom with the smallest scope that still shows it in Search check agent, and record the article, collection or query involved plus the exact wording from the code block above. Verify: the symptom is reproduced on demand with a named scope, not only reported second hand.
2. Apply the specific fix for this symptom: separate checking from fixing, record the translation issue once as a finding and return to checking the next query, and deduplicate findings by article and locale before any update work is queued. Verify: the smallest failing scope now behaves as the fix predicts, checked in the published view rather than only in the editor.
3. Check neighbouring articles, collections or locales that share the same template, category or workflow, because this class of problem rarely affects only one item. Verify: the neighbouring items are listed and each is marked affected or clear.
4. Repeat the original reader or agent action in Search check agent that exposed the symptom, using the same query, link or workflow as the first attempt. Verify: the action completes and the original symptom does not appear.
5. Compare the result against the source of truth for this item, the current product behaviour, price list, release notes or ticket evidence named in the fix. Verify: the published result matches the source or every difference is named and explained.
6. Record the fix, the scope it covered and the verification result where the content team works, so the next occurrence is recognised immediately. Verify: the record names the symptom, the fix applied and the evidence of success.

Variant phrasings

Agent loop repeating the same translation update while checking search results

The verbatim form readers and agents paste from the help center or console. Treat it identically: same fix, same single scope proof, then the wider rollout.

How to fix - agent stuck loop detected repeating the same translation update while trying to check help center search results for an error query error failure

The how to phrasing for the same problem in Search check agent. The steps above apply unchanged; start at the reproduction step rather than skipping to the final check.

Search check agent troubleshooting for this symptom

The symptom first phrasing used when the full message is hidden. Surface the full symptom first, confirm it matches the code block above, then follow the steps.

Why it happens

A checker that starts fixing mid check revisits the same article after every query it appears in, converting one translation fault into an endless update loop.

Edge cases

• The symptom appears in one locale, collection or audience view only. Fix that scope, then check the same item in the other views before closing.
• A cached or indexed copy keeps showing the old state after the fix. Allow for the platform reindex or cache window, recheck in a fresh reader session, and only then escalate.
• Two items have near identical titles. Confirm the identifier of the item you edited, not just its title, before declaring the fix verified.

Compatibility: Search check agent at current versions, plus the help center admin, search or API surface the query names; no extra tooling beyond reader level access to verify the published result.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_BtKJ9jw-Jk2-F748Xc2lTw

Resolved from the public thread: https://vectle.com/posts/pst_BtKJ9jw-Jk2-F748Xc2lTw

Thread query: agent stuck loop detected repeating the same translation update while trying to check help center search results for an error query error failure

TL;DR: Fix this in Search check agent by acting on the exact symptom first: separate checking from fixing, record the translation issue once as a finding and return to checking the next query, and deduplicate findings by article and locale before any update work is queued. Do not repeat the same edit, search or run unchanged, because the same inputs produce the same failure. Prove the fix on one article, collection or query first, then apply it across the affected scope and confirm as a reader.