refactor(tsmorph): remove duplicated import builders and unreachable guards in generateFiles

[7nohe]

Follow-up to the buildKeys dead-code removal (#205), kept out of that PR deliberately. Rebased onto current main (includes #205 and #204).

src/tsmorph/generateFiles.mts was the worst-covered file in the repo at 68.75% branch coverage, and it was uncoverable by adding tests: every uncovered branch was either structurally unreachable or a duplicate of already-tested code. This removes those branches instead.

1. Duplicated import builders

generateFiles.mts held a verbatim private copy of buildCommonFileImports / buildHookFileImports, which are already exported and tested in projectFactory.mts (tests/tsmorph/projectFactory.test.ts). The duplicated code was also the untested code. It now imports them.

2. Unreachable null guards

Three if (hook) guards could never be false — each call site pre-filtered on isPaginatable, and the builders return null only when !op.isPaginatable:

Guard	Builder	Returns null iff
generateSuspenseFile	buildUseSuspenseInfiniteQueryHook → buildInfiniteHook	buildQueryHooks.mts:271
generateInfiniteQueriesFile	buildUseInfiniteQueryHook → buildInfiniteHook	buildQueryHooks.mts:271
generatePrefetchFile	buildPrefetchInfiniteQueryFn	buildQueryHooks.mts:381

3. Extracted buildQueryOptionsFileImports

With 1 and 2 done, one uncovered branch remained: the inline buildModelImport + null-check in generateQueryOptionsFile. Same defect class as 1 — an ad-hoc import list duplicating logic projectFactory.mts already owns, and the only part of the import wiring no test reached. Moved next to its siblings and covered both the with-models and no-models paths.

4. One addStatements helper for every nullable builder

The first pass left generateFiles.mts with four nullable-builder call sites written three different ways. All four now go through one helper:

function addStatements(
  sourceFile: SourceFile,
  operations: OperationInfo[],
  build: (op: OperationInfo) => VariableStatementStructure | null,
): void

The contract — a builder returns null for operations outside its scope — is stated once in the helper's JSDoc instead of being re-derived at each site, and three near-identical explanatory comments collapse to one.

This also fixes a build regression the earlier pass introduced: narrowing (T | null)[] with a bare .filter(x => x !== null) relies on inferred type predicates, a TypeScript 5.5 feature, while package.json declares a typescript: "5.x || 6.x" peer range. Verified against typescript@5.4.5: tsc --noEmit produced three TS2345 errors before this commit and exits 0 after. Consumers of the published dist were never affected — this only broke building from source on TS 5.0–5.4.

Note this brings generateQueryOptionsFile's if (infiniteOptions) guard along too. That guard is genuinely load-bearing (its call site does not pre-filter) and is not removed — the same conditional now lives inside the helper, exercised both ways.

Coverage

	before	after
generateFiles.mts branches	68.75%	100%
repo aggregate branches	91.73%	93.47%

Verification

• npm test — 189 passed, exit 0, unmodified config
• npm run build, npm run lint — clean (107 files, zero warnings)
• tsc --noEmit under typescript@5.4.5 and @6.0.3 — both clean
• npm run preview:react diffed against a baseline generated from main: byte-identical

Note on the perFile follow-up

The motivation was to enable coverage.thresholds.perFile: true in vitest.config.ts, since the global aggregate can be moved by adding or deleting any file regardless of whether behaviour got safer.

generateFiles.mts is no longer the blocker, but perFile: true still cannot be enabled — src/parseOperations.mts fails it on functions, statements and branches:

ERROR: Coverage for functions (94.11%) does not meet global threshold (95%) for src/parseOperations.mts
ERROR: Coverage for statements (90.14%) does not meet global threshold (95%) for src/parseOperations.mts
ERROR: Coverage for branches (80%) does not meet global threshold (90%) for src/parseOperations.mts

So vitest.config.ts is deliberately untouched. Covering parseOperations.mts (uncovered lines 27, 43, 55) is the remaining prerequisite.

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Project	Deployment	Actions	Updated (UTC)
openapi-react-query-codegen	Ready	Preview	Aug 11, 2026 11:42am

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Coverage Report

Status	Category	Percentage	Covered / Total
🟢	Lines	99.2% (🎯 95%)	498 / 502
🟢	Statements	98.47% (🎯 95%)	516 / 524
🟢	Functions	99.26% (🎯 95%)	135 / 136
🟢	Branches	93.47% (🎯 90%)	215 / 230

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
src/tsmorph/generateFiles.mts	100%	100%	100%	100%
src/tsmorph/projectFactory.mts	100%	100%	100%	100%

Generated in workflow #449 for commit 5f98c3c by the Vitest Coverage Report Action