Enable cache directory path to be set explicitly (#3064)

* Enable cache directory path to be set explicitly

* Add documentation :)

docs/reference/configuration.md

@@ -444,6 +444,13 @@ Inspired by the same [Create React App](https://create-react-app.dev/docs/using-
 
 Set to `false` to prevent Snowpack from deleting the build output folder (`buildOptions.out`) between builds.
 
+### buildOptions.cacheDirPath
+
+**Type**: `string`  
+**Default**: `./node_modules/.cache/snowpack`
+
+Specify the cache directory in which bundled Node modules will be cached.
+
 ### buildOptions.webModulesUrl
 
 _NOTE:_ Deprecated, see `buildOptions.metaUrlPath`.

snowpack/src/config.ts

@@ -1,4 +1,6 @@
+import crypto from 'crypto';
 import {all as merge} from 'deepmerge';
+import projectCacheDir from 'find-cache-dir';
 import {existsSync} from 'fs';
 import {isPlainObject} from 'is-plain-object';
 import {validate} from 'jsonschema';
@@ -21,6 +23,7 @@ import {
 import {
   addLeadingSlash,
   addTrailingSlash,
+  GLOBAL_CACHE_DIR,
   NATIVE_REQUIRE,
   REQUIRE_OR_IMPORT,
   removeTrailingSlash,
@@ -31,6 +34,13 @@ import type {Awaited} from './util';
 const CONFIG_NAME = 'snowpack';
 const ALWAYS_EXCLUDE = ['**/_*.{sass,scss}', '**.d.ts'];
 
+const DEFAULT_PROJECT_CACHE_DIR =
+  projectCacheDir({name: 'snowpack'}) ||
+  // If `projectCacheDir()` is null, no node_modules directory exists.
+  // Use the current path (hashed) to create a cache entry in the global cache instead.
+  // Because this is specifically for dependencies, this fallback should rarely be used.
+  path.join(GLOBAL_CACHE_DIR, crypto.createHash('md5').update(process.cwd()).digest('hex'));
+
 // default settings
 const DEFAULT_ROOT = process.cwd();
 const DEFAULT_CONFIG: SnowpackUserConfig = {
@@ -53,6 +63,7 @@ const DEFAULT_CONFIG: SnowpackUserConfig = {
     out: 'build',
     baseUrl: '/',
     metaUrlPath: '_snowpack',
+    cacheDirPath: DEFAULT_PROJECT_CACHE_DIR,
     clean: true,
     sourcemap: false,
     watch: false,
@@ -173,6 +184,7 @@ const configSchema = {
       properties: {
         out: {type: 'string'},
         baseUrl: {type: 'string'},
+        cacheDirPath: {type: 'string'},
         clean: {type: 'boolean'},
         sourcemap: {
           oneOf: [{type: 'boolean'}, {type: 'string', enum: ['inline']}],

snowpack/src/index.ts

@@ -67,6 +67,7 @@ ${colors.bold('Flags:')}
   --help                 Show this help message.
   --version              Show the current version.
   --reload               Clear the local cache (useful for troubleshooting).
+  --cache-dir-path       Specify a custom cache directory.
   --verbose              Enable verbose log messages.
   --quiet                Enable minimal log messages.
     `.trim(),

snowpack/src/sources/local.ts

@@ -1,12 +1,10 @@
 import Arborist from '@npmcli/arborist';
-import crypto from 'crypto';
 import {
   InstallOptions,
   InstallTarget,
   resolveDependencyManifest as _resolveDependencyManifest,
   resolveEntrypoint,
 } from 'esinstall';
-import projectCacheDir from 'find-cache-dir';
 import findUp from 'find-up';
 import {existsSync, promises as fs} from 'fs';
 import * as colors from 'kleur/colors';
@@ -123,12 +121,9 @@ export class PackageSourceLocal implements PackageSource {
     this.config = config;
     this.npmConnectionOptions = getNpmConnectionOptions(config.packageOptions.source);
     if (config.packageOptions.source === 'local') {
-      this.cacheDirectory =
-        projectCacheDir({name: 'snowpack'}) ||
-        // If `projectCacheDir()` is null, no node_modules directory exists.
-        // Use the current path (hashed) to create a cache entry in the global cache instead.
-        // Because this is specifically for dependencies, this fallback should rarely be used.
-        path.join(GLOBAL_CACHE_DIR, crypto.createHash('md5').update(process.cwd()).digest('hex'));
+      this.cacheDirectory = config.buildOptions.cacheDirPath
+        ? path.resolve(config.buildOptions.cacheDirPath)
+        : GLOBAL_CACHE_DIR;
       this.packageSourceDirectory = config.root;
       this.arb = null;
     } else {

snowpack/src/types.ts

@@ -279,6 +279,7 @@ export interface SnowpackConfig {
     out: string;
     baseUrl: string;
     metaUrlPath: string;
+    cacheDirPath: string;
     clean: boolean;
     sourcemap: 'inline' | false | undefined;
     watch: boolean;