Make it easier to centrally manage tech-specific eslint rules

[daiscog]

Currently, when generating a new Angular library with the @nx/angular:library generator, the new project's .eslintrc.json comes with a set of Angular-specific overrides. E.g., for *.html files, it "extends": ["plugin:@nx/angular-template"],, and provides an empty rules object for customization.

Let's say I have a monorepo with a dozen or so Angular libraries, plus some other non-Angular ones, and I want to add a new lint rule for all Angular templates that isn't enabled OOTB by the @nx/angular-template plugin. I have to manually add that rule to the rules object in all of my Angular libraries' individual .eslintrc.json files.

It would be far better if I had a central file - say tools/eslint/configs/angular-templates.json - that all of the Angular projects in my monorepo could extend from, instead of directly extending from "plugin:@nx/angular-template". Then I can just add the additional rule in one place and have it apply to all projects.

I can set this up manually myself (and I have done so). However, it's not exactly convenient to have to either:

• Remember to edit every generated .eslintrc.json file to make it extend my centralized base config file, or
• Maintain a workspace generator that's a wrapper around the @nx/angular:library generator which edits the generated config file accordingly (and get the team to remember to use the workspace generator, not the nx one directly).

Additionally, until the issue #22477 is addressed, changes to my centralized config file won't cause cache invalidation when using inferred lint targets.

Therefore I'd like to suggest that the following changes are made to the conventional/default monorepo layout:

• tools/eslint-rules (the default dir for workspace-specific eslint rules) becomes tools/eslint/rules
• tools/eslint/configs directory is added as the default dir for workspace-specific eslint configs
• All tech-specific nx project generators create a base eslint config file under tools/eslint/configs that extends the tech-specific defaults from the @nx/eslint-plugin package (e.g., the @nx/angular:library generator creates tools/eslint/configs/angular-templates.json which "extends": ["plugin:@nx/angular-template"],, and provides an empty rules object for customization).
• The project-specific .eslintrc.json files generated by the tech-specific project generators extend the base eslint config file under tools/eslint/configs instead of extending the @nx/eslint-plugin config directly.
• Finally, either:
  • Fix Project Crystal eslint plugin does not include extended eslint config files in lint target inputs #22477 so these additional base config files are part of the inputs to the lint target where they are used, or
  • The hard-coded inputs for the inferred lint targets have {workspaceRoot}/tools/eslint/configs/**/* added to them

These changes would make it much easier by default to manage common eslint configs across a large and varied monorepo.