[claude]

Three mistakes a person can make at the command line still printed an internal stack trace, after #876 made the CLI's own usage errors one error: line. Each is now one plain line saying what to fix. Exit codes are unchanged (1) and generated output is untouched.

Before / after

A path flag with nothing after it (-i, -o, --output=):

$ json2ts schema.json -o
error: TypeError [ERR_INVALID_ARG_TYPE]: The "paths[1]" argument must be of type string. Received type boolean (true)
    at resolve (node:path:1272:7)
    at /…/dist/src/cli.js:196:107
    … 8 more frames

$ json2ts schema.json -o
error: --output (-o) needs a path after it, e.g. -o schema.d.ts

An invalid schema (compile() already prints one line per rule it breaks; the CLI then printed the empty ValidationError it throws):

$ echo '{"type":"array","minItems":-1}' | json2ts
error: Error at key "null" in file "NoName": When minItems exists, minItems >= 0
error: ValidationError
    at /…/dist/src/index.js:176:19
    at Generator.next (<anonymous>)
    at fulfilled (/…/dist/src/index.js:5:58)

$ echo '{"type":"array","minItems":-1}' | json2ts
error: Error at key "null" in file "NoName": When minItems exists, minItems >= 0

A $ref that does not resolve (a missing or unparsable file, a pointer to nothing; json-schema-ref-parser's error was printed whole, with its stack and fields):

$ json2ts schema.json      # {"properties":{"x":{"$ref":"./nothere.json"}}}
error: ResolverError: Error opening file /…/nothere.json: ENOENT: no such file or directory, open '/…/nothere.json'
    at Object.read (file:///…/json-schema-ref-parser/dist/lib/resolvers/file.js:40:19) {
  source: '/…/nothere.json',
  path: null,
  code: 'ERESOLVER',
  toJSON: [Function: bound toJSON],
  ioErrorCode: 'ENOENT'
}

$ json2ts schema.json
error: Error opening file /…/nothere.json: ENOENT: no such file or directory, open '/…/nothere.json'

When the resolver's message does not name the file the $ref sits in (a pointer into another file that has no such definition), the line says which file: error: Missing $ref pointer "#/definitions/nope". Token "nope" does not exist. (in /…/other.json). A pointer into the schema itself gets no suffix (the resolver's source for it is just the working directory). With --$refOptions.continueOnError, every collected error gets its own line.

Also: invalid JSON on standard input said Error parsing JSON in file "null"; it now says Error parsing JSON from standard input.

What is deliberately unchanged

• A file that cannot be read (json2ts -i missing.json) and malformed JSON or YAML in a file still print the stack, as CLI: print a usage error as one error: … line, and parse --inferStringEnumKeysFromValues=false as false #876 chose: they name the path, and the stack says where in the program it failed.
• The validator's in file "NoName" label for a schema piped in is the name the generated root type is derived from, so it is not touched here.

How

src/cli.ts: --input/--output given as boolean true (nothing after the flag) or '' is a UsageError, checked before the value reaches isDynamicPattern or path.resolve. The catch block prints e.message for a UsageError, one message per error for json-schema-ref-parser's JSONParserError / JSONParserErrorGroup, nothing more for a ValidationError, and the error itself (with stack) for anything else. src/utils.ts: the stdin parse message.

Tests

Eight new cliFailTests in test/cli.test.ts (-o at the end of the line, --output=, -i alone, invalid schema on stdin, invalid JSON on stdin, a $ref to a missing file, a $ref to a missing pointer in another file, a $ref to a missing pointer in the schema itself); each asserts exit 1, the message, and where it applies that stderr is one line with no at frame. All fail on master. CI=true bun run test: 688 pass, lint, format and typecheck clean.