Add Istanbul Instrumenter

Add istanbul-lib-instrument for Karma Coverage

Angular v22 makes istanbul-lib-instrument an optional peer dependency of @angular/build, used to instrument code for Karma coverage. Since optional peers are not installed automatically, this migration adds istanbul-lib-instrument to devDependencies when the workspace has a project that runs unit tests with Karma, so Karma coverage keeps working. An existing version is preserved.

Karma usage is detected on any target using the @angular-devkit/build-angular:karma or @angular/build:karma builders, or the @angular/build:unit-test / @nx/angular:unit-test executors with the runner option set to karma. Targets that inherit their executor or runner from an nx.json targetDefaults entry are detected too.

Examples

project.json

Before:

// project.json
{
  "targets": {
    "test": {
      "executor": "@nx/angular:unit-test",
      "options": {
        "runner": "karma",
      },
    },
  },
}

After (package.json):

// package.json
{
  "devDependencies": {
    "istanbul-lib-instrument": "^6.0.3",
  },
}

nx.json (targetDefaults)

A project whose test target inherits its executor and runner from an nx.json targetDefaults entry is also detected:

// nx.json
{
  "targetDefaults": {
    "test": {
      "executor": "@nx/angular:unit-test",
      "options": {
        "runner": "karma",
      },
    },
  },
}

// apps/app1/project.json
{
  "targets": {
    "test": {},
  },
}

istanbul-lib-instrument is added to package.json as shown above.