Add package for sharing jest configuration for upcoming Features (#7198)

* Add package for shared jest configurations for Lens applications, Features and libraries.

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Add root level script for running unit tests in monorepo mindset

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

* Ignore coverage files from VCS

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

---------

Signed-off-by: Janne Savolainen <janne.savolainen@live.fi>

packages/infrastructure/jest/monorepo-root-config.js

@@ -0,0 +1,73 @@
+const path = require("path");
+const glob = require("glob");
+const { omit } = require("lodash/fp");
+
+const getProjectColor = (projectNumber) => {
+  const colors = [
+    "red",
+    "green",
+    "yellow",
+    "magenta",
+    "cyan",
+    "white",
+    "redBright",
+    "greenBright",
+    "yellowBright",
+    "blueBright",
+    "magentaBright",
+    "cyanBright",
+    "whiteBright",
+  ];
+
+  return colors[projectNumber % colors.length];
+};
+
+const nonMultiProjectConfigs = [
+  "coverageDirectory",
+  "coverageProvider",
+  "coverageReporters",
+  "collectCoverage",
+  "collectCoverageFrom",
+  "coveragePathIgnorePatterns",
+  "coverageThreshold",
+];
+
+const toJestMultiProjectConfig = (
+  { packageJson, jestConfig, packagePath },
+  projectNumber
+) => ({
+  rootDir: packagePath,
+
+  displayName: {
+    name: packageJson.name,
+    color: getProjectColor(projectNumber),
+  },
+
+  ...omit(nonMultiProjectConfigs, jestConfig),
+});
+
+const getJestConfigsAndPackageJsons = (rootDir) => {
+  const packageJsonPaths = glob
+    .sync(`${rootDir}/packages/**/jest.config.js`, {
+      ignore: "./**/node_modules/**/*",
+    })
+    .map((filePath) => path.dirname(filePath));
+
+  return packageJsonPaths.map((packagePath) => ({
+    packagePath,
+    packageJson: require(`${packagePath}/package.json`),
+    jestConfig: require(`${packagePath}/jest.config.js`),
+  }));
+};
+
+module.exports = (rootDir) => ({
+  projects: getJestConfigsAndPackageJsons(rootDir).map(
+    toJestMultiProjectConfig
+  ),
+
+  watchPlugins: [
+    "jest-watch-typeahead/filename",
+    "jest-watch-typeahead/testname",
+    "jest-watch-select-projects",
+  ],
+});