Add JUnit reporter

packages/docs/src/content/docs/features/reporters.md

@@ -9,6 +9,7 @@ Knip provides the following built-in reporters:
 - `codeowners`
 - `compact`
 - `json`
+- `junit`
 - `markdown`
 - `symbol` (default)
 
@@ -76,6 +77,43 @@ The keys match the [reported issue types][1]. Example usage:
 knip --reporter json
 ```
 
+### JUnit
+
+The built-in `junit` reporter output is meant to be saved to an XML file. This
+can be achieved by providing the `path` value using `--reporter-options`. It
+reports issues in JUnit XML format, which should be readable by CI tools such as
+Bitbucket, Jenkins, etc. For example:
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<testsuites name="Knip report" tests="4" failures="4">
+  <testsuite name="Unused files" tests="1" failures="1">
+    <testcase tests="1" failures="1" name="Unused files" classname="src/unused.ts">
+      <failure message="Unused files" type="Unused files">Unused files: src/unused.ts</failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="Unlisted dependencies" tests="2" failures="2">
+    <testcase tests="1" failures="1" name="Unlisted dependencies" classname="src/index.ts">
+      <failure message="Unlisted dependencies - unresolved" type="Unlisted dependencies">Unlisted dependencies: "unresolved" inside src/index.ts</failure>
+    </testcase>
+    <testcase tests="1" failures="1" name="Unlisted dependencies" classname="src/index.ts">
+      <failure message="Unlisted dependencies - @org/unresolved" type="Unlisted dependencies">Unlisted dependencies: "@org/unresolved" inside src/index.ts</failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="Unresolved imports" tests="1" failures="1">
+    <testcase tests="1" failures="1" name="Unresolved imports" classname="src/index.ts:8:23">
+      <failure message="Unresolved imports - ./unresolved" type="Unresolved imports">Unresolved imports: "./unresolved" inside src/index.ts:8:23</failure>
+    </testcase>
+  </testsuite>
+</testsuites>
+```
+
+Example usage:
+
+```sh
+knip --reporter json --reporter-options '{"path": "/test-results/knip.xml"}'
+```
+
 ### Markdown
 
 The built-in `markdown` reporter output is meant to be saved to a Markdown file.

packages/knip/package.json

@@ -63,6 +63,7 @@
     "easy-table": "1.2.0",
     "enhanced-resolve": "^5.17.1",
     "fast-glob": "^3.3.2",
+    "fast-xml-parser": "^4.5.0",
     "jiti": "^2.3.3",
     "js-yaml": "^4.1.0",
     "minimist": "^1.2.8",

packages/knip/src/reporters/index.ts

@@ -1,6 +1,7 @@
 import codeowners from './codeowners.js';
 import compact from './compact.js';
 import json from './json.js';
+import junit from './junit.js';
 import markdown from './markdown.js';
 import symbols from './symbols.js';
 
@@ -10,4 +11,5 @@ export default {
   codeowners,
   json,
   markdown,
+  junit,
 };

packages/knip/src/reporters/junit.ts

@@ -0,0 +1,154 @@
+import fs from 'node:fs';
+import { XMLBuilder } from 'fast-xml-parser';
+import { resolve, dirname, toRelative } from '../util/path.js';
+import { getTitle } from './util.js';
+import type { ReporterOptions, IssueSet, IssueRecords, Issue } from '../types/issues.js';
+import type { Entries } from 'type-fest';
+
+interface IssuesEntry {
+  entry: string;
+  issues: Issue[];
+}
+
+type ExtraReporterOptions = {
+  path?: string;
+};
+
+type Failure = {
+  '@_message': string;
+  '@_type': string;
+  '#text': string;
+};
+
+type TestCase = {
+  '@_tests': number;
+  '@_failures': number;
+  '@_name': string;
+  '@_classname': string;
+  failure: Failure;
+};
+
+type TestSuite = {
+  '@_name': string;
+  '@_tests': number;
+  '@_failures': number;
+  testcase: TestCase[];
+};
+
+export default ({ report, issues, counters, options }: ReporterOptions) => {
+  let totalIssues = 0;
+  let testSuite: TestSuite[] = [];
+
+  for (const [reportType, isReportType] of Object.entries(report) as Entries<typeof report>) {
+    if (isReportType) {
+      const title = getTitle(reportType);
+      const count = counters[reportType];
+      const isSet = issues[reportType] instanceof Set;
+      const issuesForType = isSet
+        ? Array.from(issues[reportType] as IssueSet)
+        : Object.entries(issues[reportType] as IssueRecords).map(([entry, errors]) => {
+            const items = Object.values(errors);
+            const issues = items.flatMap(item => (item.symbols ? item.symbols : { ...item }));
+            return { entry, issues };
+          });
+
+      if (issuesForType.length > 0) {
+        let testCase: TestCase[] = [];
+        if (isSet) {
+          const setTestCases = (issuesForType as string[]).map(issue => ({
+            '@_tests': 1,
+            '@_failures': 1,
+            '@_name': title,
+            '@_classname': toRelative(issue),
+            failure: {
+              '@_message': title,
+              '@_type': title,
+              '#text': `${title}: ${toRelative(issue)}`,
+            },
+          }));
+          testCase.push(...setTestCases);
+        } else {
+          const entriesTestCases = (issuesForType as IssuesEntry[]).flatMap(typeIssues =>
+            typeIssues.issues.map(issue => {
+              let entry = typeIssues.entry;
+              if ('line' in issue && 'col' in issue) {
+                entry = `${typeIssues.entry}:${issue.line}:${issue.col}`;
+              }
+              return {
+                '@_tests': 1,
+                '@_failures': 1,
+                '@_name': title,
+                '@_classname': entry,
+                failure: {
+                  '@_message': `${title} - ${issue.symbol}`,
+                  '@_type': title,
+                  '#text': `${title}: "${issue.symbol}" inside ${entry}`,
+                },
+              };
+            })
+          );
+          testCase.push(...entriesTestCases);
+        }
+
+        if (testCase.length > 0) {
+          testSuite.push({
+            '@_name': title,
+            '@_tests': count,
+            '@_failures': count,
+            testcase: testCase,
+          });
+
+          totalIssues += count;
+        }
+      }
+    }
+  }
+
+  if (totalIssues > 0) {
+    let opts: ExtraReporterOptions = {};
+
+    try {
+      opts = options ? JSON.parse(options) : opts;
+    } catch (err) {
+      console.error('Error occured while parsing options:', err);
+    }
+
+    const xml = {
+      '?xml': {
+        '@_version': '1.0',
+        '@_encoding': 'UTF-8',
+      },
+      testsuites: {
+        '@_name': 'Knip report',
+        '@_tests': totalIssues,
+        '@_failures': totalIssues,
+        testsuite: testSuite,
+      },
+    };
+
+    const builder = new XMLBuilder({
+      attributeNamePrefix: '@_',
+      format: true,
+      processEntities: false,
+      ignoreAttributes: false,
+    });
+    const outputXML = builder.build(xml);
+
+    if (opts.path) {
+      const dir = dirname(opts.path);
+
+      if (!fs.existsSync(dir)) {
+        fs.mkdirSync(dir, { recursive: true });
+      }
+
+      try {
+        fs.writeFileSync(resolve(opts.path), outputXML, 'utf-8');
+        console.log('Knip results file successfully written.');
+      } catch (err) {
+        console.error('Error occured while writing knip results file: ', err);
+      }
+    } else {
+      console.log(outputXML);
+    }
+  }
+};

packages/knip/test/cli-reporter-junit.test.ts

@@ -0,0 +1,36 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { resolve } from '../src/util/path.js';
+import { execFactory } from './helpers/exec.js';
+
+const cwd = resolve('fixtures/module-resolution-non-std');
+
+const exec = execFactory(cwd);
+
+test('knip --reporter junit', () => {
+  const xml = `
+<?xml version="1.0" encoding="UTF-8"?>
+<testsuites name="Knip report" tests="4" failures="4">
+  <testsuite name="Unused files" tests="1" failures="1">
+    <testcase tests="1" failures="1" name="Unused files" classname="src/unused.ts">
+      <failure message="Unused files" type="Unused files">Unused files: src/unused.ts</failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="Unlisted dependencies" tests="2" failures="2">
+    <testcase tests="1" failures="1" name="Unlisted dependencies" classname="src/index.ts">
+      <failure message="Unlisted dependencies - unresolved" type="Unlisted dependencies">Unlisted dependencies: "unresolved" inside src/index.ts</failure>
+    </testcase>
+    <testcase tests="1" failures="1" name="Unlisted dependencies" classname="src/index.ts">
+      <failure message="Unlisted dependencies - @org/unresolved" type="Unlisted dependencies">Unlisted dependencies: "@org/unresolved" inside src/index.ts</failure>
+    </testcase>
+  </testsuite>
+  <testsuite name="Unresolved imports" tests="1" failures="1">
+    <testcase tests="1" failures="1" name="Unresolved imports" classname="src/index.ts:8:23">
+      <failure message="Unresolved imports - ./unresolved" type="Unresolved imports">Unresolved imports: "./unresolved" inside src/index.ts:8:23</failure>
+    </testcase>
+  </testsuite>
+</testsuites>`;
+
+  const out = exec('knip --reporter junit').stdout;
+  assert.equal(out.trim(), xml.trim());
+});