fix(typescript-flow): emit type aliases for top-level non-object types

[schani]

Bug

With --just-types on a top-level array, the TypeScript/Flow renderer emitted no output at all (exit 0, silent). A top-level map had the same problem. A top-level primitive (e.g. a string) worked fine and correctly emitted type Foo = string;.

Repro:

echo '[1, 2, 3.14]' | quicktype --lang ts --just-types --top-level Foo

Before: nothing is printed.
After: export type Foo = number[];

Root cause

TypeScriptFlowBaseRenderer.emitTypes() only emitted a top-level type alias when the top-level type was primitive (t.isPrimitive()). Arrays and maps are not primitives, so they fell through the check and got no declaration at all — and since they also have no name of their own (unlike classes/enums/unions, which get emitted separately by forEachNamedType), nothing was ever emitted for them.

Fix

Changed the condition in emitTypes() to emit a top-level alias whenever the top-level type has no directly-reachable named type of its own, using the existing directlyReachableSingleNamedType helper (already used by several other language renderers — C#, Dart, Java, JavaScript, PHP, JavaScript PropTypes — for the equivalent decision). This correctly covers primitives, arrays, and maps, while still skipping top levels that are themselves (or resolve to) a named class/enum/union, since those already get their own declaration via forEachNamedType.

Also added the export keyword to the emitted alias to match the export interface / export enum / export type convention used everywhere else in this renderer (and matching the output the original issue expected: export type Foo = number[];).

Test coverage

• test/unit/typescript-flow-top-level-alias.test.ts: unit tests asserting the emitted top-level alias text for TypeScript/Flow top-level arrays and top-level maps, plus a regression test that a map whose value type claims the top-level name is not double-declared. A unit test was used here (per repo conventions) because the primary e2e round-trip fixtures compile/run the full converter code, which doesn't exercise --just-types output — the driver programs would compile identically whether or not the top-level alias declaration itself is present, so a fixture can't detect this specific regression.
• test/inputs/schema/empty-object.schema (+ .1.json): a new bare top-level map JSON Schema fixture input, enabled for the typescript and flow fixtures (which exercise the fix in the full/non---just-types code path too), and skipped for renderers that don't support a bare top-level map at all (JavaScript PropTypes, JavaScript, PHP, TypeScript Zod, TypeScript Effect Schema) — a pre-existing, unrelated limitation.

Verification (local)

• npm run build passes.
• npm run test:unit — 176 tests passed, including the new ones.
• QUICKTEST=true FIXTURE=typescript script/test — all 79 tests passed.
• QUICKTEST=true FIXTURE=schema-typescript script/test — all 71 tests passed (including the new empty-object.schema).
• Manual repro confirmed fixed:

  $ echo '[1, 2, 3.14]' | node dist/index.js --lang ts --just-types --top-level Foo
  export type Foo = number[];
  

  Top-level string and top-level object behavior unchanged (still correct).
• Flow's own fixture (flow check / flow-node) could not be run locally because the flow toolchain isn't installed in this environment; CI will validate it.

Fixes #1122

🤖 Generated with Claude Code

[schani]

Reopening to retrigger CI (no run was dispatched for the latest commit).

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[github-actions]

Generated-output differences

39 files differ — 10 modified, 29 new, 0 deleted
1945 changed lines — +1941 / −4

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