Add and configure ESLint and update configuration for Prettier (#617)

* Add ESLint, update Prettier

* Update docs

* Update tests

* Update licenses

* Fix review points

src/cache-distributions/constants.ts

@@ -1,2 +1 @@
-const CACHE_DEPENDENCY_BACKUP_PATH: string = '**/pyproject.toml';
-export {CACHE_DEPENDENCY_BACKUP_PATH};
+export const CACHE_DEPENDENCY_BACKUP_PATH = '**/pyproject.toml';

src/cache-distributions/pip-cache.ts

@@ -15,7 +15,7 @@ class PipCache extends CacheDistributor {
 
   constructor(
     private pythonVersion: string,
-    cacheDependencyPath: string = '**/requirements.txt'
+    cacheDependencyPath = '**/requirements.txt'
   ) {
     super('pip', cacheDependencyPath);
   }

src/find-pypy.ts

@@ -65,17 +65,14 @@ export async function findPyPyVersion(
   ));
 
   if (!installDir) {
-    ({
-      installDir,
-      resolvedPythonVersion,
-      resolvedPyPyVersion
-    } = await pypyInstall.installPyPy(
-      pypyVersionSpec.pypyVersion,
-      pypyVersionSpec.pythonVersion,
-      architecture,
-      allowPreReleases,
-      releases
-    ));
+    ({installDir, resolvedPythonVersion, resolvedPyPyVersion} =
+      await pypyInstall.installPyPy(
+        pypyVersionSpec.pypyVersion,
+        pypyVersionSpec.pythonVersion,
+        architecture,
+        allowPreReleases,
+        releases
+      ));
   }
 
   const pipDir = IS_WINDOWS ? 'Scripts' : 'bin';
@@ -145,7 +142,7 @@ export function parsePyPyVersion(versionSpec: string): IPyPyVersionSpec {
   const versions = versionSpec.split('-').filter(item => !!item);
 
   if (/^(pypy)(.+)/.test(versions[0])) {
-    let pythonVersion = versions[0].replace('pypy', '');
+    const pythonVersion = versions[0].replace('pypy', '');
     versions.splice(0, 1, 'pypy', pythonVersion);
   }
 

src/install-pypy.ts

@@ -63,7 +63,7 @@ export async function installPyPy(
   }
 
   const {foundAsset, resolvedPythonVersion, resolvedPyPyVersion} = releaseData;
-  let downloadUrl = `${foundAsset.download_url}`;
+  const downloadUrl = `${foundAsset.download_url}`;
 
   core.info(`Downloading PyPy from "${downloadUrl}" ...`);
 
@@ -143,7 +143,7 @@ async function createPyPySymlink(
   const pythonMinor = semver.minor(version);
   const pypyBinaryPostfix = pythonBinaryPostfix === 2 ? '' : '3';
   const pypyMajorMinorBinaryPostfix = `${pythonBinaryPostfix}.${pythonMinor}`;
-  let binaryExtension = IS_WINDOWS ? '.exe' : '';
+  const binaryExtension = IS_WINDOWS ? '.exe' : '';
 
   core.info('Creating symlinks...');
   createSymlinkInFolder(

src/setup-python.ts

@@ -23,7 +23,7 @@ async function cacheDependencies(cache: string, pythonVersion: string) {
 }
 
 function resolveVersionInput() {
-  let versions = core.getMultilineInput('python-version');
+  const versions = core.getMultilineInput('python-version');
   let versionFile = core.getInput('python-version-file');
 
   if (versions.length && versionFile) {

src/utils.ts

@@ -1,3 +1,4 @@
+/* eslint no-unsafe-finally: "off" */
 import * as cache from '@actions/cache';
 import * as core from '@actions/core';
 import fs from 'fs';
@@ -71,7 +72,7 @@ export function getPyPyVersionFromPath(installDir: string) {
  */
 export function readExactPyPyVersionFile(installDir: string) {
   let pypyVersion = '';
-  let fileVersion = path.join(installDir, PYPY_VERSION_FILE);
+  const fileVersion = path.join(installDir, PYPY_VERSION_FILE);
   if (fs.existsSync(fileVersion)) {
     pypyVersion = fs.readFileSync(fileVersion).toString().trim();
   }