Add node's caching implementation (#2)

* first iteration for implementation of caching

* add logs

* add debug line

* fix build command

* fix path

* add possible post-if

* remove braces

* test new action post-if variant

* work on built-in caching

* remove post-if

* pass version

* work on yarn support

* fix return value

* change names and remove logs

* worked on resolving comments

* check post-if for null

* add success() condition

* remove primary key field

* work on resolving comments

* remove logs

* resolving comments

* resolving comments

* resolving comments

* resolving comments

* fix getpackageManagerVersion

* run clean for unstaged changes

* fix falling version tests

* work on resolving comments

* resolving comments

* fix comment

* resolve comments

* Add tests to cover node's caching (#3)

* add tests to cover node's caching

* work on fixing tests

* fix e2e tests

* rebuild and fix test

* fixing tests

* change name of describes, it and fix test

* add names for jobs

* fix issue

src/cache-utils.ts

@@ -0,0 +1,84 @@
+import * as core from '@actions/core';
+import * as exec from '@actions/exec';
+
+type SupportedPackageManagers = {
+  [prop: string]: PackageManagerInfo;
+};
+
+export interface PackageManagerInfo {
+  lockFilePatterns: Array<string>;
+  getCacheFolderCommand: string;
+}
+
+export const supportedPackageManagers: SupportedPackageManagers = {
+  npm: {
+    lockFilePatterns: ['package-lock.json', 'yarn.lock'],
+    getCacheFolderCommand: 'npm config get cache'
+  },
+  yarn1: {
+    lockFilePatterns: ['yarn.lock'],
+    getCacheFolderCommand: 'yarn cache dir'
+  },
+  yarn2: {
+    lockFilePatterns: ['yarn.lock'],
+    getCacheFolderCommand: 'yarn config get cacheFolder'
+  }
+};
+
+export const getCommandOutput = async (toolCommand: string) => {
+  const {stdout, stderr, exitCode} = await exec.getExecOutput(toolCommand);
+
+  if (stderr) {
+    throw new Error(stderr);
+  }
+
+  return stdout;
+};
+
+const getPackageManagerVersion = async (
+  packageManager: string,
+  command: string
+) => {
+  const stdOut = await getCommandOutput(`${packageManager} ${command}`);
+
+  if (!stdOut) {
+    throw new Error(`Could not retrieve version of ${packageManager}`);
+  }
+
+  return stdOut;
+};
+
+export const getPackageManagerInfo = async (packageManager: string) => {
+  if (packageManager === 'npm') {
+    return supportedPackageManagers.npm;
+  } else if (packageManager === 'yarn') {
+    const yarnVersion = await getPackageManagerVersion('yarn', '--version');
+
+    core.debug(`Consumed yarn version is ${yarnVersion}`);
+
+    if (yarnVersion.startsWith('1.')) {
+      return supportedPackageManagers.yarn1;
+    } else {
+      return supportedPackageManagers.yarn2;
+    }
+  } else {
+    return null;
+  }
+};
+
+export const getCacheDirectoryPath = async (
+  packageManagerInfo: PackageManagerInfo,
+  packageManager: string
+) => {
+  const stdOut = await getCommandOutput(
+    packageManagerInfo.getCacheFolderCommand
+  );
+
+  if (!stdOut) {
+    throw new Error(`Could not get cache folder path for ${packageManager}`);
+  }
+
+  core.debug(`${packageManager} path is ${stdOut}`);
+
+  return stdOut;
+};