fix(data,export): collapse the STEP string escaper's two TS copies into one (#3300)

[BIMvoice]

Closes part of #3300.

The three sites, before this change

packages/data/src/step-serializers.ts	escapeStepString, module-private
packages/export/src/step-serialization.ts	escapeStepString, exported
rust/export/src/step_text.rs	escape (pub(crate))

The two TypeScript bodies were byte-identical: same three-transform pipeline (backslash doubling, quote doubling, one-space-per-control-char), same \X2\/\X4\ non-ASCII directive thresholds, same 32–126 basic-graphic-range check. packages/export/package.json already declares "@ifc-lite/data": "workspace:^" — one direction, no cycle — so there was no dependency reason for the second copy.

Verified today's three implementations actually agree

Before collapsing anything, I ran the same awkward inputs — a bare backslash, an apostrophe, a BMP non-ASCII character, an already-\X2\-looking sequence, control-char runs, and the empty string — through all three (TS data, TS export, and a temporary Rust unit test calling step_text::escape directly). All three agreed on every case. No live divergence bug; this was pure duplication.

What changed

• @ifc-lite/data's step-serializers.ts now exports escapeStepString (was module-private) and is re-exported from the package's index.ts.
• @ifc-lite/export's step-serialization.ts deletes its own escapeStepString/encodeNonAsciiStepDirectives body and instead does import { escapeStepString } from '@ifc-lite/data' + export { escapeStepString }, so all five existing call sites (property-value-serialization.ts, step-georeferencing.ts, retype.ts, step-property-set-generators.ts, attribute-slot-types.ts) keep importing from ./step-serialization.js unchanged.
• scripts/api-surface.json gains the one new @ifc-lite/data export entry (checked with check-api-surface.mjs, matches exactly).

The Rust implementation is left alone: sharing it with TypeScript would need a wasm adapter, which is out of scope here, so the TS/Rust agreement stays pinned by a hand-kept vector test rather than shared code — same reasoning #3297 gave for the sibling lexical-rule issue (#3303).

#3284's parity test

A prior fix (#3284) added a RUST_VECTORS table + it.each block in both TS test files, asserting each copy's control-character-run output matched Rust's observed output. With one TS implementation left:

• packages/export/src/step-serialization.test.ts's two describe blocks (non-ASCII directive tests + control-char-run parity table) are replaced by a single small "re-export resolves to a working function" smoke test — coverage of the actual behavior would otherwise be a second copy of the same assertions against the same underlying function.
• packages/data/src/step-serializers.test.ts keeps the full RUST_VECTORS parity suite (comment updated to say it's the one remaining TS copy) and gains new direct tests of escapeStepString (backslash, apostrophe, non-ASCII, already-escaped-looking text, empty string) now that the function is exported instead of reached only through serializeValue/generateHeader.

Mutation-checked: reverting the backslash-doubling regex to a no-op reds 3 tests in data's suite and 2 in export's re-export smoke test, restored cleanly by SHA.

The fourth, partial copy — left alone

packages/encoding/src/ifc-string.ts's encodeIfcString is a genuinely different implementation, not a drop-in: it encodes the whole Latin-1 range as \X\HH (not \X2\HHHH\X0\), routes a backslash into that same arm as \X\5C instead of doubling it, and does no '' quote-doubling or control-to-space mapping. It has no production call sites (only its own ifc-string.parity.test.ts). Folding it in is explicitly out of scope per the issue.

Verification

CARGO_TARGET_DIR=/tmp/t-3300 cargo test -p ifc-lite-export   # 356+ passed, 0 failed (unchanged)
pnpm exec turbo build                                          # full workspace build, clean
pnpm exec turbo typecheck --filter=@ifc-lite/data --filter=@ifc-lite/export --filter=@ifc-lite/codegen
pnpm exec turbo test --filter=@ifc-lite/data --filter=@ifc-lite/export --filter=@ifc-lite/codegen
  @ifc-lite/data:    Test Files 20 passed | Tests 231 passed
  @ifc-lite/export:  Test Files 78 passed, 2 skipped | Tests 1023 passed, 30 skipped
  @ifc-lite/codegen: Test Files 9 passed | Tests 122 passed
node scripts/check-api-surface.mjs   # ✅ matches snapshot
node scripts/check-changesets.mjs    # 4 pending, all naming workspace packages
pnpm exec oxlint <changed files>     # clean

🤖 Generated with Claude Code

https://claude.ai/code/session_01QPHChk3Ve9N519A4kY7436

[coderabbitai]

Warning

Review limit reached

• Run on-demand review

_{This review includes 7 billable files and costs up to $1.75.}

Or wait 29 minutes for your next included review.

View limit details

Limit details: You’ve used all 2 included reviews currently available.

Learn how review limits work.

Review configuration:

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 4efa100f-2efa-487b-b529-a959efacfaae

📥 Commits

Reviewing files that changed from the base of the PR and between 5a431e5 and fc70ee9.

📒 Files selected for processing (7)

• .changeset/collapse-step-escaper-copies.md
• packages/data/src/index.ts
• packages/data/src/step-serializers.test.ts
• packages/data/src/step-serializers.ts
• packages/export/src/step-serialization.test.ts
• packages/export/src/step-serialization.ts
• scripts/api-surface.json

---

_{Comment @coderabbitai help to get the list of available commands.}

[github-actions]

Viewer benchmark

✅ No threshold regressions detected.

01_Snowdon_Towers_Sample_Structural(1).ifc

Baseline recorded 2026-07-01T20:31:05.538Z on github-actions ubuntu-latest, viewer-benchmark-ci (headless Chrome, SwiftShader ANGLE), production build.

Metric	Current	Baseline	Delta	Threshold	Status
firstBatchWaitMs	1472ms	2905ms	-49.3%	+50%	✅
firstVisibleGeometryMs	1914ms	3652ms	-47.6%	+50%	✅
streamCompleteMs	2286ms	3598ms	-36.5%	+50%	✅
spatialReadyMs	1067ms	1032ms	+3.4%	+50%	✅
metadataCompleteMs	1562ms	3063ms	-49.0%	+50%	✅
totalWallClockMs	2400ms	3700ms	-35.1%	+50%	✅

AC20-FZK-Haus.ifc

Baseline recorded 2026-07-01T20:30:59.972Z on github-actions ubuntu-latest, viewer-benchmark-ci (headless Chrome, SwiftShader ANGLE), production build.

Metric	Current	Baseline	Delta	Threshold	Status
firstBatchWaitMs	279ms	1075ms	-74.0%	+50%	✅
firstVisibleGeometryMs	1144ms	1572ms	-27.2%	+50%	✅
streamCompleteMs	1609ms	1980ms	-18.7%	+50%	✅
spatialReadyMs	799ms	915ms	-12.7%	+50%	✅
metadataCompleteMs	1173ms	1392ms	-15.7%	+50%	✅
totalWallClockMs	2800ms	3300ms	-15.2%	+50%	✅

Refresh the baseline from a CI run: dispatch the Benchmark workflow with record_baseline, download the benchmark-baseline artifact, and commit baseline.json (see tests/benchmark/README.md).

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

2 Skipped Deployments

Project	Deployment	Actions	Updated (UTC)
ifc-lite-dev	Ignored	Preview	Aug 28, 2026 6:49am
ifc-lite-viewer-embed	Ignored		Aug 28, 2026 6:49am