code-coverage-backend

This is the backend part of the code-coverage plugin. It takes care of processing various coverage formats and standardizing them into a single json format, used by the frontend.

Installation

# From your Backstage root directory
yarn --cwd packages/backend add @backstage/plugin-code-coverage-backend

First create a codecoverage.ts file here: packages/backend/src/plugins. Now add the following as its content:

diff --git a/packages/backend/src/plugins/codecoverage.ts b/packages/backend/src/plugins/codecoverage.ts
--- /dev/null
+++ b/packages/backend/src/plugins/codecoverage.ts
@@ -0,0 +1,15 @@
+import { createRouter } from '@backstage/plugin-code-coverage-backend';
+import { Router } from 'express';
+import { PluginEnvironment } from '../types';
+
+export default async function createPlugin(
+  env: PluginEnvironment,
+): Promise<Router> {
+  return await createRouter({
+    config: env.config,
+    discovery: env.discovery,
+    database: env.database,
+    urlReader: env.reader,
+    logger: env.logger,
+  });
+}

Finally we need to load the plugin in packages/backend/src/index.ts, make the following edits:

diff --git a/packages/backend/src/index.ts b/packages/backend/src/index.ts
--- a/packages/backend/src/index.ts
+++ b/packages/backend/src/index.ts
@@ -28,6 +28,7 @@ import scaffolder from './plugins/scaffolder';
 import proxy from './plugins/proxy';
 import techdocs from './plugins/techdocs';
 import search from './plugins/search';
+import codeCoverage from './plugins/codecoverage';
 import { PluginEnvironment } from './types';
 import { ServerPermissionClient } from '@backstage/plugin-permission-node';
 import { DefaultIdentityClient } from '@backstage/plugin-auth-node';
@@ -85,6 +86,9 @@ async function main() {
   const techdocsEnv = useHotMemoize(module, () => createEnv('techdocs'));
   const searchEnv = useHotMemoize(module, () => createEnv('search'));
   const appEnv = useHotMemoize(module, () => createEnv('app'));
+  const codeCoverageEnv = useHotMemoize(module, () =>
+    createEnv('code-coverage'),
+  );

   const apiRouter = Router();
   apiRouter.use('/catalog', await catalog(catalogEnv));
@@ -93,6 +97,7 @@ async function main() {
   apiRouter.use('/techdocs', await techdocs(techdocsEnv));
   apiRouter.use('/proxy', await proxy(proxyEnv));
   apiRouter.use('/search', await search(searchEnv));
+  apiRouter.use('/code-coverage', await codeCoverage(codeCoverageEnv));

   apiRouter.use(notFoundHandler());

New Backend System

The code coverage backend plugin has support for the new backend system, here's how you can set that up:

In your packages/backend/src/index.ts make the following changes:

+ backend.add(import('@backstage/plugin-explore-backend'));

Configuring your entity

In order to use this plugin, you must set the backstage.io/code-coverage annotation.

metadata:
  annotations:
    backstage.io/code-coverage: enabled

There's a feature to only include files that are in VCS in the coverage report, this is helpful to not count generated files for example. To enable this set the backstage.io/code-coverage annotation to scm-only.

metadata:
  annotations:
    backstage.io/code-coverage: scm-only

Note: It may be required to set the backstage.io/source-location annotation, however this should generally not be needed.

API

Adding a Cobertura report

POST a Cobertura XML file to /report

Example:

// curl -X POST -H "Content-Type:text/xml" -d @cobertura.xml "localhost:7007/api/code-coverage/report?entity=component:default/entity-name&coverageType=cobertura"
{
  "links": [
    {
      "href": "http://localhost:7007/api/code-coverage/report?entity=component:default/entity-name",
      "rel": "coverage"
    }
  ]
}

Adding a JaCoCo report

POST a JaCoCo XML file to /report

Example:

// curl -X POST -H "Content-Type:text/xml" -d @jacoco.xml "localhost:7007/api/code-coverage/report?entity=component:default/entity-name&coverageType=jacoco"
{
  "links": [
    {
      "href": "http://localhost:7007/api/code-coverage/report?entity=component:default/entity-name",
      "rel": "coverage"
    }
  ]
}

Adding a LCOV report

POST a LCOV INFO file to /report

Example:

// curl -X POST -H "Content-Type:text/plain" -d @coverage.info "localhost:7007/api/code-coverage/report?entity=component:default/entity-name&coverageType=lcov"
{
  "links": [
    {
      "href": "http://localhost:7007/api/code-coverage/report?entity=component:default/entity-name",
      "rel": "coverage"
    }
  ]
}

Reading json coverage

GET /report

Example:

// curl localhost:7007/api/code-coverage/report?entity=component:default/entity-name
{
  "aggregate": {
    "branch": {
      "available": 0,
      "covered": 0,
      "missed": 0,
      "percentage": 0
    },
    "line": {
      "available": 5,
      "covered": 4,
      "missed": 1,
      "percentage": 80
    }
  },
  "entity": {
    "kind": "Component",
    "name": "entity-name",
    "namespace": "default"
  },
  "files": [
    {
      "branchHits": {},
      "filename": "main.go",
      "lineHits": {
        "117": 12,
        "142": 8,
        "34": 8,
        "42": 0,
        "58": 6
      }
    }
  ]
}

Coverage history

GET /history

Example

// curl localhost:7007/api/code-coverage/history?entity=component:default/entity-name
{
  "entity": {
    "kind": "Component",
    "name": "entity-name",
    "namespace": "default"
  },
  "history": [
    {
      "branch": {
        "available": 0,
        "covered": 0,
        "missed": 0,
        "percentage": 0
      },
      "line": {
        "available": 299,
        "covered": 116,
        "missed": 183,
        "percentage": 38.8
      },
      "timestamp": 1615490766141
    },
    {
      "branch": {
        "available": 0,
        "covered": 0,
        "missed": 0,
        "percentage": 0
      },
      "line": {
        "available": 299,
        "covered": 116,
        "missed": 183,
        "percentage": 38.8
      },
      "timestamp": 1615406307929
    }
  ]
}

Configuration

Configure the plugin in your app-config.yaml:

codeCoverage:
  bodySizeLimit: 100kb # Defaults to 100kb, see https://www.npmjs.com/package/body-parser#limit