feat(lint): add import rule to prevent circular dependencies

Current Behavior

Importing from within a given library (.e.g. @proj/lib-a) should use relative paths (.e.g. ./module) instead of the paths in path-mappings (e.g. @proj/lib-a). Currently, there is no way to restrict this via linting.

Expected Behavior

Importing from @proj/lib-a from within @proj/lib-a should result in a linting error.

We can use the following rules for each library’s tslint.json or .eslintrc:

TSLint

https://palantir.github.io/tslint/rules/import-blacklist/

    "import-blacklist": [true, "rxjs/Rx", "@nx-examples/shared/jsxify"]

ESLint

https://eslint.org/docs/rules/no-restricted-imports

"no-restricted-imports": ["error", "import1", "import2"]

Caveats

If the workspace has this rule in their root linting config, the generated rule should include what is there because it will be completely overwritten otherwise.

We should also write a migration which will add this rule to existing projects within the workspace.

Related Issues

#738 #741

[twittwer]

Currently, we’re doing this via a workspace schematic: https://gist.github.com/twittwer/d1adb85f873b02b14b6f52d2aa9ec4f3#file-index-ts-L124

Would be nice to get this out of the box 😄

[llwt]

Not stale 😃 Could still really use this, we might contribute this if someone doesn’t beat us to it.