test: do not hide mocha errors for nested suites

.github/CODEOWNERS

@@ -259,6 +259,7 @@
 /packages/dd-trace/test/iitm.spec.js @DataDog/lang-platform-js
 /packages/dd-trace/test/log.spec.js @DataDog/lang-platform-js
 /packages/dd-trace/test/msgpack/ @DataDog/lang-platform-js
+/packages/dd-trace/test/mocha-hooks.spec.js @DataDog/lang-platform-js
 /packages/dd-trace/test/noop.spec.js @DataDog/lang-platform-js
 /packages/dd-trace/test/pkg.spec.js @DataDog/lang-platform-js
 /packages/dd-trace/test/plugin_manager.spec.js @DataDog/lang-platform-js

packages/dd-trace/test/mocha-hooks.spec.js

@@ -0,0 +1,210 @@
+'use strict'
+
+const assert = require('node:assert/strict')
+const { execFile } = require('node:child_process')
+const fs = require('node:fs')
+const os = require('node:os')
+const path = require('node:path')
+const util = require('node:util')
+
+const execFileAsync = util.promisify(execFile)
+const mochaBin = path.join(__dirname, '../../../node_modules/mocha/bin/mocha.js')
+const coreSetupPath = path.join(__dirname, 'setup/core.js')
+
+describe('mocha hooks setup', () => {
+  it('suppresses after all errors when a before all in the same suite already failed', async () => {
+    const result = await runFixture(`
+      describe('suite', () => {
+        let resource
+
+        before(() => {
+          throw new Error('setup failed')
+        })
+
+        after(() => {
+          resource.close()
+        })
+
+        it('does something', () => {})
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['setup failed'])
+  })
+
+  it('suppresses after all errors when a test in the same suite already failed', async () => {
+    const result = await runFixture(`
+      describe('suite', () => {
+        after(() => {
+          throw new Error('cleanup failed')
+        })
+
+        it('fails for the real reason', () => {
+          throw new Error('test failed')
+        })
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['test failed'])
+  })
+
+  it('suppresses after each errors when the current test already failed', async () => {
+    const result = await runFixture(`
+      describe('suite', () => {
+        afterEach(() => {
+          throw new Error('cleanup failed')
+        })
+
+        it('fails for the real reason', () => {
+          throw new Error('test failed')
+        })
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['test failed'])
+  })
+
+  it('continues running tests after suppressing an after each error', async () => {
+    const result = await runFixture(`
+      describe('suite', () => {
+        afterEach(function () {
+          if (this.currentTest.title === 'fails for the real reason') {
+            throw new Error('cleanup failed')
+          }
+        })
+
+        it('fails for the real reason', () => {
+          throw new Error('test failed')
+        })
+
+        it('still runs', () => {})
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['test failed'])
+    assert.deepStrictEqual(getPassTitles(result), ['still runs'])
+  })
+
+  it('suppresses after each errors when a before each in the same suite already failed', async () => {
+    const result = await runFixture(`
+      describe('suite', () => {
+        beforeEach(() => {
+          throw new Error('setup failed')
+        })
+
+        afterEach(() => {
+          throw new Error('cleanup failed')
+        })
+
+        it('does something', () => {})
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['setup failed'])
+  })
+
+  it('suppresses outer after all errors when a nested test already failed', async () => {
+    const result = await runFixture(`
+      describe('outer suite', () => {
+        after(() => {
+          throw new Error('outer cleanup failed')
+        })
+
+        describe('inner suite', () => {
+          it('fails for the real reason', () => {
+            throw new Error('inner test failed')
+          })
+        })
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['inner test failed'])
+  })
+
+  it('suppresses outer after each errors when a nested before each already failed', async () => {
+    const result = await runFixture(`
+      describe('outer suite', () => {
+        afterEach(() => {
+          throw new Error('outer cleanup failed')
+        })
+
+        describe('inner suite', () => {
+          beforeEach(() => {
+            throw new Error('inner setup failed')
+          })
+
+          it('does something', () => {})
+        })
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['inner setup failed'])
+  })
+
+  it('suppresses outer after each errors when a nested after each already failed', async () => {
+    const result = await runFixture(`
+      describe('outer suite', () => {
+        afterEach(() => {
+          throw new Error('outer cleanup failed')
+        })
+
+        describe('inner suite', () => {
+          afterEach(() => {
+            throw new Error('inner cleanup failed')
+          })
+
+          it('passes before cleanup', () => {})
+        })
+      })
+    `)
+
+    assert.deepStrictEqual(getFailureMessages(result), ['inner cleanup failed'])
+  })
+})
+
+/**
+ * @param {string} body
+ * @returns {Promise<MochaJsonResult>}
+ */
+async function runFixture (body) {
+  const tmpdir = fs.mkdtempSync(path.join(os.tmpdir(), 'dd-trace-mocha-hooks-'))
+  const fixture = path.join(tmpdir, 'fixture.spec.js')
+  fs.writeFileSync(fixture, `'use strict'
+
+require(${JSON.stringify(coreSetupPath)})
+
+${body}
+`)
+
+  try {
+    const { stdout } = await execFileMocha(fixture)
+    return JSON.parse(stdout)
+  } finally {
+    fs.rmSync(tmpdir, { force: true, recursive: true })
+  }
+}
+
+/**
+ * @param {string} fixture
+ * @returns {Promise<{ stdout: string }>}
+ */
+async function execFileMocha (fixture) {
+  try {
+    return await execFileAsync(process.execPath, [mochaBin, '--no-config', '--reporter', 'json', fixture])
+  } catch (err) {
+    if (!err || typeof err !== 'object' || !('stdout' in err) || typeof err.stdout !== 'string') throw err
+    return { stdout: err.stdout }
+  }
+}
+
+/**
+ * @param {MochaJsonResult} result
+ * @returns {string[]}
+ */
+function getFailureMessages (result) {
+  return result.failures.map(failure => failure.err.message)
+}
+
+function getPassTitles (result) {
+  return result.passes.map(pass => pass.title)
+}