Nothing is type-checked in CI, and tsc --noEmit silently checks zero files #948

Problem

Nothing in this repo is type-checked, and the obvious command silently checks nothing.

tsconfig.json is a solution-style config — "files": [] plus references to tsconfig.app.json and tsconfig.node.json. So:

$ npx tsc --noEmit --listFiles | wc -l
0

That command exits 0 having checked zero files. The command that actually works is tsc -b --noEmit, which follows the project references:

$ npx tsc -b --noEmit | grep -c "error TS"
214

There is also no typecheck script in package.json, and vite build strips types without checking them. The only type enforcement today is ESLint's type-aware rules (@typescript-eslint/no-unsafe-* and friends), which catch a useful subset but not assignability.

This is easy to be fooled by: tsc --noEmit is what most people reach for, it prints nothing, and that reads as success.

Current state

214 errors, roughly two-thirds in test files:

  in test files    143
  in source files   69

Concentrated rather than spread — the top offender alone is 75:

  75  src/utils/searchUtils.test.tsx
  18  src/components/Badge.test.tsx
  17  src/components/PathwayCard.test.tsx
  15  src/components/BadgeArray.test.tsx
  11  src/components/PathwayCard.tsx
  10  src/components/MultiLineChart.tsx

Common shapes: fixtures that predate the v2 schema and are missing required fields, import ... assert instead of with, and computed variant/className lists widening to string.

There is already a branch for this

origin/typecheck (4 months old, 12 commits) adds exactly the missing pieces:

• a typecheck script (tsc -b) in package.json
• a typecheck step in .github/workflows/node-lint.yml
• typecheck as a required check in .github/rulesets/gitflow-main.json and gitflow-production.json

It has no PR and is mostly Merge branch 'main' into typecheck commits, which reads like it was kept alive but never landed — presumably because turning the check on fails immediately against a few hundred errors.

Suggested approach

1. Land the tooling from origin/typecheck but non-blocking at first (report, don't fail), so the number is visible and can't grow unnoticed.
2. Burn it down in slices — the four test files above are ~125 of the 214, and most look like stale fixtures rather than real defects.
3. Flip it to a required check once it reaches zero.

Fixing the tsconfig.json trap is worth doing regardless of the rest: either give the root config an include, or document that tsc -b is the real command.

Context

Found while working on #872 / PR #946, where I reported "typecheck clean" several times on the strength of a command that was checking nothing. Two genuine type errors in that PR's own new code were only caught once tsc -b was run. PR #946 also reduced the count from 251 to 214 as a side effect of fixing a props type that made all four BadgeArray callers fail.