feat(plugin-coverage): get coverage paths using nx

Author: Tlacenka

code-pushup.config.ts

@@ -11,7 +11,9 @@ import {
   packageJsonPerformanceGroupRef,
   packageJsonPlugin,
 } from './dist/examples/plugins';
-import coveragePlugin from './dist/packages/plugin-coverage';
+import coveragePlugin, {
+  getNxCoveragePaths,
+} from './dist/packages/plugin-coverage';
 import eslintPlugin, {
   eslintConfigFromNxProjects,
 } from './dist/packages/plugin-eslint';
@@ -54,32 +56,7 @@ const config: CoreConfig = {
         command: 'npx',
         args: ['nx', 'run-many', '-t', 'unit-test', '--coverage'],
       },
-      reports: [
-        {
-          resultsPath: 'coverage/cli/unit-tests/lcov.info',
-          pathToProject: 'packages/cli',
-        },
-        {
-          resultsPath: 'coverage/core/unit-tests/lcov.info',
-          pathToProject: 'packages/core',
-        },
-        {
-          resultsPath: 'coverage/models/unit-tests/lcov.info',
-          pathToProject: 'packages/models',
-        },
-        {
-          resultsPath: 'coverage/utils/unit-tests/lcov.info',
-          pathToProject: 'packages/utils',
-        },
-        {
-          resultsPath: 'coverage/plugin-eslint/unit-tests/lcov.info',
-          pathToProject: 'packages/plugin-eslint',
-        },
-        {
-          resultsPath: 'coverage/plugin-coverage/unit-tests/lcov.info',
-          pathToProject: 'packages/plugin-coverage',
-        },
-      ],
+      reports: await getNxCoveragePaths(['unit-test', 'integration-test']),
     }),
     fileSizePlugin({
       directory: './dist/examples/react-todos-app',

packages/plugin-coverage/README.md

@@ -117,6 +117,7 @@ The plugin accepts the following parameters:
 
 - `coverageTypes`: An array of types of coverage that you wish to track. Supported values: `function`, `branch`, `line`. Defaults to all available types.
 - `reports`: Array of information about files with code coverage results - paths to results, path to project root the results belong to. LCOV format is supported for now.
+  - If you have an `nx` monorepo, you can adjust our helper function `getNxCoveragePaths` to get the path information automatically.
 - (optional) `coverageToolCommand`: If you wish to run your coverage tool to generate the results first, you may define it here.
 - (optional) `perfectScoreThreshold`: If your coverage goal is not 100%, you may define it here in range 0-1. Any score above the defined threshold will be given the perfect score. The value will stay unaffected.
 

packages/plugin-coverage/package.json

@@ -6,5 +6,13 @@
     "@code-pushup/utils": "*",
     "parse-lcov": "^1.0.4",
     "zod": "^3.22.4"
+  },
+  "peerDependencies": {
+    "@nx/devkit": "^17.0.0"
+  },
+  "peerDependenciesMeta": {
+    "@nx/devkit": {
+      "optional": true
+    }
   }
 }

packages/plugin-coverage/src/index.ts

@@ -2,3 +2,4 @@ import { coveragePlugin } from './lib/coverage-plugin';
 
 export default coveragePlugin;
 export type { CoveragePluginConfig } from './lib/config';
+export { getNxCoveragePaths } from './lib/nx/coverage-paths';

packages/plugin-coverage/src/lib/nx/coverage-paths.ts

@@ -0,0 +1,47 @@
+import type { ProjectGraphProjectNode } from '@nx/devkit';
+import { join } from 'node:path';
+import { CoverageResult } from '../config';
+
+/**
+ *
+ * @param coverageFolder root folder containing all coverage results
+ * @param targets nx targets to be used for measuring coverage, test by default
+ * @returns An array of coverage result information for the coverage plugin.
+ */
+export async function getNxCoveragePaths(
+  targets: string[] = ['test'],
+): Promise<CoverageResult[]> {
+  const { createProjectGraphAsync } = await import('@nx/devkit');
+  const { nodes } = await createProjectGraphAsync({ exitOnError: false });
+
+  const coverageResults = targets.map(target => {
+    const relevantNodes = Object.values(nodes).filter(graph =>
+      hasNxTarget(graph, target),
+    );
+
+    return relevantNodes
+      .map(node => node.data)
+      .map<CoverageResult>(projectConfig => {
+        const { reportsDirectory } = projectConfig.targets?.[target]
+          ?.options as {
+          reportsDirectory: string;
+        };
+
+        const rootToReportsDir = join(projectConfig.root, reportsDirectory);
+
+        return {
+          pathToProject: projectConfig.root,
+          resultsPath: join(rootToReportsDir, 'lcov.info'),
+        };
+      });
+  });
+
+  return coverageResults.flat();
+}
+
+function hasNxTarget(
+  project: ProjectGraphProjectNode,
+  target: string,
+): boolean {
+  return project.data.targets != null && target in project.data.targets;
+}