test(ui): cover yamlAutocompletion, fragmentUtils, jsonStream, nodeIssues, samplePipelineOrdering, mse, deepEqual

[staging-devin-ai-integration]

Summary

Phase 3 coverage initiative — Stream E (UI utils, pure logic). Test-only PR; no production code touched.

Adds Vitest unit tests for seven previously-uncovered modules in ui/src/utils/. Style mirrors PR #440 / #441 (describe/it, table-driven where natural) and PR #425 (vi.stubGlobal + vi.unstubAllGlobals for DOM globals).

Module	Lines	Tests added	What's covered
deepEqual.ts	41	34	primitives (incl. Object.is semantics for NaN and -0), arrays (lengths, order, nesting, sparse), plain objects (key sets, nesting, null-prototype, {a: undefined} vs {}), non-plain objects (Map/Date/class instances, function ref identity)
jsonStream.ts	70	16	extractJsonValues framing: single, concatenated }{, partial-trailing-remainder, nested objects/arrays, braces inside strings, escaped quotes/backslashes, top-level arrays, leading garbage, empty input
nodeIssues.ts	73	25	shortSessionId (dash split, no-dash whole-string return, empty-first-segment 8-char fallback), formatIssueDetails (null/undefined → null, JSON shape, 180-char truncation + ellipsis, circular-ref returns null), formatIssueSummary (with/without details), summarizeNodeIssues severity ordering (Failed < Degraded < Recovering < Stopped, then nodeId)
samplePipelineOrdering.ts	50	16	compareSamplePipelinesByName (Intl numeric collation, id tiebreaker), orderSamplePipelinesSystemFirst (partition + sort, no mutation), matchesSamplePipelineQuery (empty/whitespace queries, name/description/id substring, case-insensitive, trim)
mse.ts	41	12	normalizeMimeType (opus/vp9/AAC-LC/AVC baseline injection, pass-through when codecs= already present), canUseMseForMimeType with vi.stubGlobal('MediaSource', …) covering: missing global, supported, unsupported, missing isTypeSupported, pre-codec'd type
fragmentUtils.ts	164	14	generateNodeId sequential ids, fragmentToReactFlow (1-to-1 node/edge count, audioGain type selection, grid layout math, NodeDefinition wiring, missing-def fallback, missing-needs-warn path via mocked logger), extractFragment (selection set, needs scalar vs array forms, omits needs with no deps, label/kind fallbacks), round-trip through both
yamlAutocompletion.ts	452	30	Captures the override completion source via a vi.hoisted mock of @codemirror/autocomplete, then drives it with synthetic EditorState + CompletionContext: mode: (dynamic/oneshot filter), kind: (NodeDefinition listing, categories detail), needs: (scalar form + array - element form + js-yaml-throws regex fallback), params: name completions (description + default detail), params: value completions (enum / boolean / number-with-default+range / string-default with quoted label and unquoted apply), and the fall-through-to-null path

Total: 147 new tests. Local: 1011/1011 passing (bun run test:run), just lint-ui clean for new files (the 6 remaining warnings predate this PR and are in AssetLibrary.tsx, ConfigurableNode.tsx, InspectorPane.tsx, DesignView.tsx, StreamView.tsx).

All new files have SPDX headers. No new dependencies.

Notes

• Parent session: https://staging.itsdev.in/sessions/a088e863cbbd473b9be4a57529fc674b
• The yamlAutocompletion mock pattern uses vi.hoisted to share state with the (hoisted) vi.mock factory — same pattern used elsewhere in the repo for similar capture-the-callback scenarios.
• No production bugs surfaced while writing these tests.

Review & Testing Checklist for Human

Risk: green (test-only, isolated to new files).

• Skim ui/src/utils/yamlAutocompletion.test.ts — confirm the mock-and-capture approach is acceptable repo-wide (the alternative would be exposing the completion source as a named export, but that would be a production-code change and this PR is test-only).
• Confirm the deepEqual(-0, 0) === false assertion matches the intended Object.is semantics of deepEqual (the implementation uses Object.is, which treats -0 and +0 as distinct).
• CI green on the codecov UI flag.

Link to Devin session: https://staging.itsdev.in/sessions/d3d99542ef1b4daa81e29a9aaffdc353
Requested by: @streamer45

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 66.14%. Comparing base (fad6274) to head (9bc2d44).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #471      +/-   ##
==========================================
+ Coverage   65.91%   66.14%   +0.22%     
==========================================
  Files         217      220       +3     
  Lines       57530    57816     +286     
  Branches     1597     1683      +86     
==========================================
+ Hits        37922    38241     +319     
+ Misses      19602    19569      -33     
  Partials        6        6              

Flag	Coverage Δ
backend	65.01% <ø> (+0.01%)	⬆️
ui	76.77% <ø> (+1.69%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
core	84.29% <ø> (ø)
engine	75.71% <ø> (ø)
api	84.73% <ø> (ø)
nodes	67.45% <ø> (+0.04%)	⬆️
server	57.16% <ø> (ø)
plugin-native	70.93% <ø> (ø)
plugin-wasm	6.37% <ø> (ø)
ui-services	74.73% <ø> (ø)
ui-components	60.49% <ø> (ø)
see 9 files with indirect coverage changes

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