[QA] Canonical Code Coverage Teams and CODEOWNERS Assignment

Add the first draft of the TEAMS assignments,
including defaults for code coverage and teams.
After this PR, we will add a CI check to verify
all defined paths have CODEOWNERship,
and possibly code coverage teams.

Resovles #72692

scripts/canonical_codeowners.js

@@ -0,0 +1,21 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+require('../src/setup_node_env');
+require('../src/dev/code_owners').defineCodeOwners();

src/dev/code_owners/__tests__/code_owners.test.js

@@ -0,0 +1,34 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import expect from '@kbn/expect';
+import { hasPath } from '../';
+
+describe(`Code Owners`, () => {
+  describe(`hasPath predicate fn`, () => {
+    const iterable = new Map();
+    iterable.set('a', 'b');
+    it(`should return true if the iterable has the path`, () => {
+      expect(hasPath('a')(iterable)).to.be(true);
+    });
+    it(`should return false if the iterable does not have the path`, () => {
+      expect(hasPath('b')(iterable)).to.be(false);
+    });
+  });
+});

src/dev/code_owners/helpers.js

@@ -0,0 +1,47 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { pretty } from '../code_coverage/ingest_coverage/utils';
+
+export function teamName(githubHandle) {
+  const prefix = /elastic\//;
+  const dropElastic = dropPrefix(prefix);
+  const prefixedWithES = prefixed(prefix);
+
+  return prefixedWithES(githubHandle) ? dropElastic(githubHandle) : githubHandle;
+}
+
+export function hasPath(path) {
+  return (iterable) => !!iterable.has(path);
+}
+
+function prefixed(prefix) {
+  return (x) => prefix.test(x);
+}
+
+function dropPrefix(prefix) {
+  return (x) => x.replace(prefix, '');
+}
+export function hasOverrides(xs) {
+  return !!Array.isArray(xs[0]);
+}
+
+export function printMap(map) {
+  map.forEach((value, key) => console.log(key + ' -> ' + pretty(value)));
+}

src/dev/code_owners/index.js

@@ -0,0 +1,54 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import { sourceOfTruth as sot } from './owners_source_of_truth';
+import { left, right } from '../code_coverage/ingest_coverage/either';
+import { printMap, teamName, hasPath } from './helpers';
+
+export const defineCodeOwners = () => {
+  const init = new Map();
+
+  const owners = sot.reduce((acc, { title, githubHandle, pathPatterns }) => {
+    pathPatterns.forEach((path) => {
+      const handle = `@${githubHandle}`;
+      const team = teamName(githubHandle);
+
+      const whether = hasPath(path)(acc) ? right(acc) : left(acc);
+
+      const alreadyHas = (path) => (accObj) => {
+        const { owners: currOwners, teams: currTeams } = accObj.get(path);
+
+        accObj.set(path, {
+          owners: currOwners.concat(handle),
+          teams: currTeams.concat(team),
+          title,
+        });
+      };
+
+      const orNot = (path) => (accObj) =>
+        accObj.set(path, { owners: [handle], teams: [team], title });
+
+      whether.fold(orNot(path), alreadyHas(path));
+    });
+
+    return acc;
+  }, init);
+
+  printMap(owners);
+};