name	check-translations
description	Diff English source strings against each translation, report stale/missing keys, and optionally update translations using parallel agents
disable-model-invocation	true

Translation Sync Checker

Uses src/lang/TRANSLATION_MANIFEST.json to track which English commit each translation was last synced to, then generates targeted diffs to identify what changed.

Scope

We translate: src/lang/*.js files only (editoria11y's own strings)
We do NOT translate: src/sa11y-lang/*.js files (managed in the Sa11y repo)
We do report: changes in src/sa11y-lang/en.js for cross-repo sync review

Manifest location

src/lang/TRANSLATION_MANIFEST.json — contains:

englishSources: the editoria11y English base files (baseAll.js, baseEnglishOnly.js)
sa11yEnglishSource: the Sa11y English source (src/sa11y-lang/en.js) — monitored for changes but not translated here
baseline: the commit all translations were initially baselined to
translations: map of { "src/lang/xx.js": "<commit>" } for each translation file

Step 1: Identify what changed in English

Diff from the oldest translation commit to HEAD:

git diff <oldest_commit> HEAD -- src/lang/baseAll.js src/lang/baseEnglishOnly.js

If no diff, all translations are up to date — skip to Step 3.

If there is a diff, summarize:

Added keys (new strings that need translation)
Removed keys (strings that should be deleted from translations)
Changed values (English wording changed — translation needs update)

Step 2: Update translations (parallel agents)

Launch one Agent per language in parallel (use a single message with multiple Agent tool calls). Each agent receives the same English diff context.

Deploy the first 10 agents in one batch, then pipeline: launch another agent as soon as one finishes, rather than waiting for a full batch to complete.

Shared spec file (recommended when 3+ languages are affected)

Instead of inlining the full English diff in every agent prompt, write the diff once to a shared file (e.g., /tmp/ed11y-translation-spec.md) and point each agent at it. This keeps per-prompt tokens low and guarantees consistency across languages. The spec file should contain:

The OLD/NEW English for every changed key
Recurring patterns to watch for (e.g., "all Alt text: prefixes are now wrapped in <strong>...</strong>")
The critical rules block

Critical agent instructions

Include ALL of the following rules in every agent prompt — these were learned from production failures:

CRITICAL RULES FOR WRITING TRANSLATION FILES:

1. NEVER use curly/smart quotes (' ' " ") as JavaScript string delimiters.
   Only use straight single quotes ('), straight double quotes ("), or backticks (`).

2. When a translated string contains an apostrophe (e.g., Italian "l'immagine",
   French "l'image"), you MUST either:
   - Use backtick delimiters: `L'immagine è marcata...`
   - Or escape the apostrophe: 'L\'immagine è marcata...'
   NEVER use curly quotes to work around apostrophes.

3. Use the Edit tool with targeted old_string/new_string replacements.
   Do NOT use the Write tool to rewrite the entire file — this risks
   corrupting unchanged content or introducing encoding issues.

4. After the last edit is made, verify the file parses by running:
   node -c <filepath>
   If it fails, fix the syntax error before finishing. Each node command pauses for user error, so try to group this into as few commands as possible.

5. Preserve the exact indentation style of the file (tabs, not spaces).

6. Keep all HTML markup, ${why.fix}, %(NAME) placeholders, and URLs
   exactly as-is — only translate the human-readable text.

7. INVISIBLE UNICODE HAZARD (especially fr.js): the Edit tool does byte-exact
   matching on old_string. French uses U+202F (narrow no-break space) and
   sometimes U+00A0 (no-break space) before ":", ";", "?", "!". These look
   identical to regular spaces when displayed. Other languages may use
   U+2011 (non-breaking hyphen) or U+2019 (curly apostrophe) inside words.
   If Edit fails with "String to replace not found" on text that looks
   correct, suspect invisible characters.

8. ESCAPE HATCH: if Edit fails twice on what looks like the same string,
   STOP LOOPING. Report back to the main process that Edit cannot match
   the target — include the target text and the error. The main process
   can inspect raw bytes via Bash + python3 and do the surgical edit.
   Do not invent XXX/YYY marker strategies or try to guess Unicode
   codepoints — those have historically left files corrupted.

Agent prompt pattern

Update the [Language] translation file at [path].

English changes since last sync:
- ADDED testName: KEY = "English string"
- ADDED tip: KEY = `<p>English tip...</p>`
- CHANGED tip KEY — new English: `<p>New English...</p>`
- REMOVED: OLD_KEY

CRITICAL RULES FOR WRITING TRANSLATION FILES:
[paste the rules block above]

Read the file first. Use the Edit tool for targeted replacements.
Insert new keys alphabetically among existing keys.
Match the existing translation style and tone.
Run `node -c [filepath]` when done to verify syntax.

After all agents complete

Run npm run build to verify everything compiles
Fix any syntax errors (most likely: unescaped apostrophes or curly quotes)
Update each translation's commit in TRANSLATION_MANIFEST.json to current HEAD

Step 3: Report Sa11y English changes

Always check for changes in the Sa11y English source, even if editoria11y strings haven't changed:

git diff <oldest_commit> HEAD -- src/sa11y-lang/en.js

If there are changes, print a structured report for human review:

## Sa11y English String Changes (for cross-repo sync)

These changes are in `src/sa11y-lang/en.js` and need to be synced
to the Sa11y repo and other consuming projects.

### New keys
| Key | Value |
|-----|-------|
| NEW_KEY | "New English string" |

### Changed keys
| Key | Old value | New value |
|-----|-----------|-----------|
| CHANGED_KEY | "Old text" | "New text" |

### Removed keys
| Key | Old value |
|-----|-----------|
| OLD_KEY | "Was this" |

This report is for the developer to manually sync across repos — do NOT attempt to translate or modify src/sa11y-lang/ files.

English dialect variants

src/lang/en-gb.js (British) and src/lang/en-ca.js (Canadian) are thin dialect overlays over baseAll.js. They do NOT re-translate everything — they import baseAll.js and override only the keys that differ in spelling or word choice.

When baseAll.js gains a new string that contains dialect-sensitive words (e.g. color, colorblind, organize, visualize, emphasize, capitalize, -ize/-ise verbs, -or/-our nouns), both dialect files may need a matching override entry:

en-gb (British): override color→colour, organize→organise, visualize→visualise, emphasize→emphasise, capitalize→capitalise, and any other -ize/-our differences.
en-ca (Canadian): override -our words only (color→colour, colorblind→colourblind). Canadian English keeps American -ize endings, so most other words stay as-is.

Tips that embed ${why.headings} need the whole tip rewritten in en-gb.js because the embedded block contains "organise". The list of affected tips is in en-gb.js — look at britishTips.

Files to skip

These are NOT translation targets — never modify them:

src/lang/en.js — English bundle assembler
src/lang/en-us.js — English US variant assembler
src/lang/_template.js — template file
src/lang/baseAll.js — English source (testNames, interfaceStrings, tips)
src/lang/baseEnglishOnly.js — English-only overrides
src/sa11y-lang/*.js — all Sa11y lang files (managed externally)

File structure reference

Each src/lang/*.js translation file contains:

An import of its corresponding src/sa11y-lang/*.js file
A testNames object (short alert titles)
A tips object (detailed tooltip HTML using template literals with ${why.fix}, %(placeholder) syntax)
An interfaceStrings object (UI labels)
An export combining everything with Sa11y strings via Object.assign