Reference

Task inheritance

Define once under .moon/tasks/**, inherit many places. Mission: stop copy-pasting lint/test/format.

Where tasks live

• Shared: .moon/tasks/**/* — inherited by matching projects
• Local: <project>/moon.* — unique tasks + merge/override

Paths/globs in inherited tasks are relative to the project root, not the workspace root (unless prefixed / for workspace-relative).

inheritedBy (who gets this file)

# .moon/tasks/node-frontend-library.yml
inheritedBy:
  toolchain: 'node'
  stack: 'frontend'
  layer: 'library'

• Conditions: file(s), language(s), layer(s), stack(s), tag(s), toolchain(s)
• All listed conditions must match (AND)
• Empty / omitted → inherit by all projects
• tags / toolchains: clauses and / or / not

Project filters (after inherit)

# project moon.yml
workspace:
  inheritedTasks:
    include: ['lint', 'test']   # allow-list (optional)
    exclude: ['format']         # drop after include
    rename:
      buildApplication: 'build'

Order: include → exclude → rename.

Same-name merge

Global + local task with same ID → merge. Strategies on args/deps/env/inputs/outputs/toolchains:

• append (default) — local after global
• prepend — local before global
• replace — local wins entirely for that field
• preserve — keep global only (rare)

tasks:
  build:
    args: '--no-stats'
    options:
      mergeArgs: 'append'
      mergeInputs: 'replace'

Prefer command (mergeable) over script (replace-only) when inheriting.

Implicit extras (global task files)

• implicitDeps — e.g. ^:build on every inherited task
• implicitInputs — e.g. package.json always invalidates
• Always applied; ignore mergeDeps/mergeInputs options

Inputs / outputs (why inheritance still needs them)

• inputs — what changes force a re-run (files, globs, env)
• outputs — build artifacts for cache hydration
• No useful inputs → “always run” pain returns