#Script types

A script entry declares exactly one variant. The variant is decided by which of four keys is present: command, extends, serial or parallel.

type PerOsCommand = {
  default: string;
  win32?: string;
  darwin?: string;
  linux?: string;
};

type ScriptBase = {
  description?: string;
  cwd?: string;
  env?: Record<string, string>;
  envFile?: string;
};

type Lifecycle = {
  timeout?: number;
  retries?: number;
  retryDelay?: number | 'exponential';
  killSignal?: string;
  killTimeout?: number;
  interactive?: boolean;
};

export type Script =
  | (ScriptBase & Lifecycle & { command: string | PerOsCommand; dependsOn?: string[] })
  | (ScriptBase & Lifecycle & { extends: string; appendArgs?: string[]; dependsOn?: string[] })
  | (ScriptBase & { serial: string[]; continueOnError?: boolean })
  | (ScriptBase & { parallel: string[]; continueOnError?: boolean; successPolicy?: SuccessPolicy });

The same rules are enforced twice: by these types when the config is written, and by Rune when it is loaded. A fixture test asserts that anything tsc accepts, Rune accepts.

#Shared fields

Every variant accepts these.

#The command variant

test: {
  command: 'vitest run --coverage',
  description: 'Run unit tests',
}

command is handed to a shell, so operators work: tsc --build && node dist/main.js, jest | tee test.log, cross-env NODE_ENV=test vitest. Rune parses none of it. The shell is cmd.exe on Windows and /bin/sh elsewhere, or whatever npm_config_script_shell names.

#Per-OS commands

Where one command cannot serve every platform, command takes an object. default is required and is used for any platform without its own entry.

clean: {
  command: {
    default: 'rm -rf dist',
    win32: 'if exist dist rmdir /s /q dist',
  },
}

Selection happens at resolution time, from the platform Rune is running on. rune inspect prints the selected string, not the object.

#The extends variant

test: {
  extends: 'test',
  appendArgs: ['--maxWorkers=1'],
}

Resolves another script's command and appends arguments to it. Chains are followed transitively and cycles are rejected by name. See Inheritance and overrides.

#The group variants

ci: { serial: ['build', 'test', 'lint'] },
dev: { parallel: ['dev:api', 'dev:web'] },

Members are script names. A group carries no command and no lifecycle options; those belong on the members. See Groups.

#Validation

Every rejection names the script it came from, because a config with thirty entries makes a message about "the shape" useless.

An unknown field is an error rather than a warning. Silent acceptance of retires instead of retries means the option never takes effect and nothing says so.

Diagnostics go to stderr on every platform. Standard output belongs to the script.