TEST: Comprehensive missing test coverage across 7 modules — 20+ edge cases and feature paths untested, CI never runs coverage

[devinoldenburg]

Summary

The test suite has significant coverage gaps across multiple modules. While the 52 existing tests are well-written and cover the happy paths thoroughly, several important edge cases, feature paths, and rendering scenarios are untested. Additionally, CI never runs with code coverage instrumentation, so the actual coverage percentage is unknown.

CI Gap: No coverage reporting

The package.json defines a test:coverage script:

"test:coverage": "node --experimental-test-coverage --test"

But .github/workflows/ci.yml:29 only runs:

- name: Unit tests
  run: node --test

Coverage is never collected in CI, so there's no way to track coverage drift across PRs.

Missing Test Coverage by Module

plugins/tps/config.js (7 existing tests)

Missing test	Why important
OPENCODE_TPS_METER_DISABLE="true"	Only "1" is tested; "true" is documented as valid
OPENCODE_TPS_METER="0" / "no" / ""	Only "off" tested; other falsy values should also disable
showSparkline, showSession, showWaits	No env override support exists, but if added, needs tests
Env var precedence: OPENCODE_TPS_METER=1 + OPENCODE_TPS_METER_DISABLE=true	Both set — which wins? Undefined behavior

plugins/tps/view.js (8 existing tests)

Missing test	Why important
showSparkline: false rendering	Sparkline is a key UI feature; its absence should be tested
showWaits: false rendering	Wait exclusion info should be omitted when disabled
Custom icon, label, unit	README documents these config options but no test verifies they render
showTotals: true	The totals line (session TPS, tokens, cost) is completely untested
showCost: true	Cost formatting in rendered view has zero test coverage
showCache: true	Cache info in rendered view has zero test coverage
Minimal detail + live streaming	Existing "minimal" test passes live: undefined so sparkline conditional is false

plugins/tps/gen.js (6 existing tests)

Missing test	Why important
GenerationTimer.snapshot()	Exists in source (gen.js:133-149) but zero tests call it
push() with repeated same-timestamp chunks (gap = 0)	Common in bursty streams; zero-gap handling is untested
setTokens() then snapshot()	Exact provider token counts should reflect in snapshot

plugins/tps/meter.js (10 existing tests)

Missing test	Why important
smooth() ramp-up from 0	The EWMA cold-start (issue #2) behavior — test would validate the fix
push() with out-of-order timestamps	Meter assumes monotonic timestamps but doesn't enforce
elapsedSec() edge cases	Very small or very large durations

plugins/tps/tps.js (9 existing tests)

Missing test	Why important
messageStats with primeTokens on active window	Prime-corrected decode TPS path is untested
aggregate with decodeSource: "active"	Only end-to-end decodeSource messages tested
calibrateRatio with custom alpha	The alpha parameter exists but is never tested with non-default values
calibrateRatio boundary: near MIN_RATIO / MAX_RATIO	Clamping behavior is untested

tests/integration.test.mjs (2 existing tests)

Missing test	Why important
End-to-end with metric: "output"	Only "generated" metric is tested in full pipeline
End-to-end with showTotals: true and showCost: true	The cost/totals rendering path is completely uncovered by integration tests
End-to-end involving calibrateRatio	The chars→tokens calibration pipeline has no integration coverage

tests/format.test.mjs (10 existing tests)

Missing test	Why important
fmtRate(999) — boundary at >= 100	Tests cover < 10, >= 10, >= 100 and >= 1000 but not exactly the boundary
sparkline with custom empty option	The empty parameter exists but is never tested
fmtMs(60000) — boundary at exactly one minute	Should render "1m00s" — edge case

Suggested Fix

1. Enable coverage in CI. Change node --test to npm run test:coverage in ci.yml.
2. Add the missing tests prioritized by risk:
   • High: showTotals/showCost view rendering (untested render path that users see)
   • High: primeTokens in messageStats (math bug potential)
   • High: GenerationTimer.snapshot() (public API, untested)
   • Medium: Integration tests with calibration pipeline
   • Medium: Format boundary values
   • Low: View custom icon/label/unit

[devinoldenburg]

Triaged as superseded. PR #141 adds focused regression tests for the reported edge cases and CI type/runtime checks; a blanket coverage policy is a separate maintenance decision.