Post-Processor System#

The postProcess option in @hey-api/openapi-ts runs arbitrary shell commands on the generated output folder after all files have been written to disk. It is typically used to auto-format or auto-lint generated TypeScript files so the output is immediately clean. 1

postProcess lives under output in the config and accepts an array of preset strings, custom command objects, or a mix of both 2:

// output/types.ts
postProcess?: ReadonlyArray<PostProcessorPreset | UserPostProcessor>;

Commands execute sequentially in the order they are declared. 1

Note: format and lint (the legacy top-level output options) are deprecated in favor of postProcess. 3

Built-in Presets#

Seven presets are available as string literals. Their full command + args expansions are defined in packages/openapi-ts/src/config/output/postprocess.ts 4:

4

Custom Commands#

Pass a { command, args } object for any tool not in the preset list 1:

postProcess: [
  { command: 'dprint', args: ['fmt', '{{path}}'] },
]

The {{path}} token is replaced at runtime with the absolute path to output.path. Presets use this same mechanism internally. 4

You can mix presets and custom commands in one array:

postProcess: ['eslint', { command: 'prettier', args: ['{{path}}', '--write'] }]

5

Opting Out / Ignoring Files#

Add the output directory to the tool's standard ignore file (e.g., .eslintignore, .prettierignore) to skip processing specific paths without removing the processor from the config. 1

Execution Path in the Codebase#

Post-processing is triggered inside createClient after generateOutput completes and only when config.dryRun is false 6:

generateOutput(context) // write .ts files
  → postprocessOutput(config.output, postProcessors, jobPrefix) // run commands

The postProcessors map imported from ./config/output/postprocess resolves preset strings to their concrete { command, args } objects before execution. 7 The actual postprocessOutput runtime is implemented in @hey-api/shared. 8

Key Source Files#