Summary

We have various custom commands leveraging the build cache. However, some of those commands do not actually depend on all devDependencies in package.json. I.e. when a dev dependency (e.g. another project in the monorepo) changes, all commands cache is invalidated even though we know it is not relevant for some of those commands.

We can ignore specific files in each project to be considered ignored for changes. However, we cannot do that for monorepo projects in dependencies. I believe it should be considered for devDependencies only though.

A small detail relevant for both - ignoring files and ignoring dependencies - is that the current file ignore works for all commands. It would be nice to have the possibility ignore files (and devDependencies) independently for each command (but keeping the common configuration for all commands).

E.g. rush-project.json

{
  "incrementalBuildIgnoredGlobs": [
    "**/*.md"
  ],

  "incrementalBuildIgnoredDevDependencies": [
    "@rushstack/foo"
  ],

  "operationSettings": [
    ...
    {
      "operationName": "foo",
      ...
      "incrementalBuildIgnoredGlobs": [
        "**/*.md", // Notice this is duplicated and not inherited. Inheritance would make it complicated to make an exception including generally ignored files
        "**/*.json"
      ],

      "incrementalBuildIgnoredDevDependencies": [
        "@rushstack/bar", // Notice the dependency `@rushstack/foo` is not ignored here
      ],
    },
    ...
  ]
}