PROMPT.md

Test Prompt: @fhir-dsl/cli

Role. You are a senior TypeScript test engineer. Your goal is to raise @fhir-dsl/cli to production-grade unit-test coverage using vitest, without modifying any source or introducing new runtime dependencies.

Project brief

fhir-dsl is a type-safe FHIR query builder + code generator monorepo (pnpm workspaces). The CLI — binary name fhir-gen — wraps @fhir-dsl/generator behind Commander.js and exposes the generate subcommand so end users can produce TypeScript types for any FHIR version or IG.

Monorepo layout: packages/<pkg>/src/ (source, colocated *.test.ts) and packages/<pkg>/test/ (separate tree, also picked up by vitest). Tests you write for this prompt go in packages/cli/test/.

Package brief

• Entry point: packages/cli/src/index.ts wires generateCommand into a Commander program named fhir-gen.
• Sole subcommand today: generateCommand in packages/cli/src/commands/generate.ts.
• Public surface: the CLI invoked from a shell; programmatically, only the exported generateCommand is consumed.
• Runtime deps: commander, @fhir-dsl/generator.

Files to read first

1. packages/cli/src/index.ts
2. packages/cli/src/commands/generate.ts
3. packages/cli/src/commands/generate.test.ts (existing coverage)
4. packages/generator/src/generator.ts (signature of the generate() the CLI calls)

Existing coverage

packages/cli/src/commands/generate.test.ts asserts that each option is registered with the right required/optional flag and default. Do not re-assert these. Focus on behavior — what the command does when invoked.

Coverage gaps to fill

Write tests in packages/cli/test/ using vitest. Cover at minimum:

1. --resources parsing. Empty string, single value, comma-separated list, whitespace around values ("Patient , Observation "), duplicate entries, and undefined (flag absent) must all be handled correctly. Mock generate() from @fhir-dsl/generator (e.g. vi.mock) and assert on the resources field passed to it.
2. --validator acceptance. native and zod are accepted; any other value must throw an Error whose message includes both the offending value and the legal values.
3. Path resolution. --out and --src must be passed through path.resolve so relative paths become absolute. Assert on the value the CLI forwards to generate().
4. Flag forwarding. Each of --ig, --cache, --expand-valuesets, --resolve-codesystems, --include-spec, --strict-extensible, and --version reaches generate() under the expected key.
5. --ig multi-value. Commander's <packages...> means repeating --ig yields an array. Confirm the CLI does not double-wrap or split on commas.
6. Missing required flag. Omitting --out or --version causes Commander to exit with a non-zero code and print a usage error. (Use program.exitOverride() / configureOutput to capture without killing the test process.)
7. Unknown flag. Passing --unknown-flag surfaces an error rather than being silently forwarded to generate().

Research directives

Read these before writing tests:

• Commander.js v12 docs: https://github.com/tj/commander.js/tree/v12.x#readme — especially exitOverride, configureOutput, parsing variadic args, and requiredOption.
• FHIR published versions list to confirm version strings the CLI accepts: https://www.hl7.org/fhir/directory.html.
• FHIR package registry URL format (IG packages like hl7.fhir.us.core@6.1.0): https://registry.fhir.org/learn.

Conventions

• vitest with globals: true (you don't need import { describe, it, ... } but keeping the imports for parity with the existing style is fine).
• No emojis anywhere — source, tests, docstrings, commit messages.
• Mock @fhir-dsl/generator's generate export at the module boundary. Do not monkey-patch generateCommand itself.
• When you need to simulate argv, prefer generateCommand.parseAsync(["node", "fhir-gen", "generate", ...]) with exitOverride set, so assertions run on Commander's thrown CommanderError / InvalidArgumentError.
• Colocate new tests in packages/cli/test/ — pick descriptive filenames (generate-resources.test.ts, generate-validator.test.ts, …).

Workflow

1. Read the source + existing test files listed above.
2. Scaffold a vi.mock("@fhir-dsl/generator", ...) helper shared by tests.
3. Write each scenario as its own it(...) block. One assertion per concept.
4. Run the gates from the repo root:

   pnpm test --filter=@fhir-dsl/cli     # or: pnpm test (full suite)
   pnpm lint
   pnpm -r typecheck

5. Iterate until all three are green.

Success criteria

• Every scenario above has at least one it(...) block.
• pnpm test, pnpm lint, pnpm -r typecheck all green.
• No test hits the network or writes to disk.
• No source files under packages/cli/src/ are modified.

Out of scope

• Refactoring the CLI or its option schema.
• End-to-end tests that actually invoke generate() against FHIR definitions (covered by the generator prompt).
• Adding new subcommands.