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-save.ts

@@ -0,0 +1,50 @@
+import * as core from '@actions/core';
+import * as cache from '@actions/cache';
+import {State} from './constants';
+import {getCacheDirectoryPath, getPackageManagerInfo} from './cache-utils';
+
+export async function run() {
+  const cacheLock = core.getInput('cache');
+  try {
+    await cachePackages(cacheLock);
+  } catch (error) {
+    core.setFailed(error.message);
+  }
+}
+
+const cachePackages = async (packageManager: string) => {
+  const state = core.getState(State.CacheMatchedKey);
+  const primaryKey = core.getState(State.CachePrimaryKey);
+
+  const packageManagerInfo = await getPackageManagerInfo(packageManager);
+  if (!packageManagerInfo) {
+    core.debug(`Caching for '${packageManager}' is not supported`);
+    return;
+  }
+
+  const cachePath = await getCacheDirectoryPath(
+    packageManagerInfo,
+    packageManager
+  );
+  if (primaryKey === state) {
+    core.info(
+      `Cache hit occurred on the primary key ${primaryKey}, not saving cache.`
+    );
+    return;
+  }
+
+  try {
+    await cache.saveCache([cachePath], primaryKey);
+    core.info(`Cache saved with the key: ${primaryKey}`);
+  } catch (error) {
+    if (error.name === cache.ValidationError.name) {
+      throw error;
+    } else if (error.name === cache.ReserveCacheError.name) {
+      core.info(error.message);
+    } else {
+      core.warning(`${error.message}`);
+    }
+  }
+};
+
+run();