Ignore falsy values in include/exclude

Author: Stephan Septh Schreiber

README.md

@@ -118,7 +118,9 @@ externals({
 ```
 Just like `exclude`, the `include` option can be a string, a regex or an array of those.
 
-> Note: this plugin uses an exact match against your imports, so if your are using some path substitution in your code, eg.:
+> Note 1 : falsy values in `include` and `exclude` are silently ignored. This allows for conditional constructs like so: `exclude: process.env.NODE_ENV === 'production' && /mydep/`.
+
+> Note2 : this plugin uses an exact match against your imports, so if your are using some path substitution in your code, eg.:
 ```js
 // in your code:
 import something from '@/mylib'   // Say '@/' is mapped to some directory

package-lock.json

@@ -37,18 +37,19 @@
   "scripts": {
     "build": "rollup -c",
     "watch": "rollup -cw",
-    "dist": "trash dist && rollup -c && tsc src/index.ts --declaration --emitDeclarationOnly --outDir dist",
-    "clean": "trash dist"
+    "types": "tsc src/index.ts --declaration --emitDeclarationOnly --outDir dist",
+    "clean": "trash dist",
+    "prepublishOnly": "npm run clean && npm run build && npm run types"
   },
   "peerDependencies": {
     "builtin-modules": "^3.1.0"
   },
   "devDependencies": {
+    "@rollup/plugin-node-resolve": "^7.1.3",
     "@wessberg/rollup-plugin-ts": "^1.2.24",
-    "rollup": "^2.4.0",
-    "rollup-plugin-node-resolve": "^5.2.0",
+    "rollup": "^2.7.6",
     "trash": "^6.1.1",
-    "tslint": "^6.1.1",
+    "tslint": "^6.1.2",
     "typescript": "^3.8.3",
     "typescript-tslint-plugin": "^0.5.5"
   }

package.json

@@ -7,6 +7,7 @@ const input = 'src/index.ts'
 const sourcemap = true
 const external = builtins.concat(Object.keys(pkg.devDependencies), Object.keys(pkg.peerDependencies))
 const tsOptions = {
+    tsconfig: cfg => ({ ...cfg, removeComments: true })
 }
 
 /** @type {import('rollup').RollupOptions} */

rollup.config.js

@@ -10,29 +10,37 @@ import { Plugin } from 'rollup'
 import * as builtinModules from 'builtin-modules'
 
 export interface ExternalsOptions {
-    packagePath: string
-    builtins: boolean
-    deps: boolean
-    devDeps: boolean
-    peerDeps: boolean
-    optDeps: boolean
-    include: string | RegExp | (string | RegExp)[]
-    exclude: string | RegExp | (string | RegExp)[]
-    /** @deprecated. Use include/exclude instead. */
-    except: string | RegExp | (string | RegExp)[]
+    /** Path/to/your/package.json file. Defaults to the one in `process.cwd()`. */
+    packagePath?: string
+    /** Mark node built-in modules like `path`, `fs`... as external. Defaults to `true`. */
+    builtins?: boolean
+    /** Mark dependencies as external. Defaults to `false`. */
+    deps?: boolean
+    /** Mark devDependencies as external. Defaults to `true`. */
+    devDeps?: boolean
+    /** Mark peerDependencies as external. Defaults to `true`. */
+    peerDeps?: boolean
+    /** Mark optionalDependencies as external. Defaults to `true`. */
+    optDeps?: boolean
+    /** Force these deps in the list of externals, regardless of other settings. Defaults to `[]`  */
+    include?: string | RegExp | (string | RegExp)[]
+    /** Exclude these deps from the list of externals, regardless of other settings. Defaults to `[]`  */
+    exclude?: string | RegExp | (string | RegExp)[]
+    /** @deprecated Use `exclude` instead. */
+    except?: string | RegExp | (string | RegExp)[]
 }
 
 /** For backward compatibility. Use `ExternalsOptions` instead. */
 export type ExternalOptions = ExternalsOptions
 
 // The plugin implementation
-export default function externals(options: Partial<ExternalsOptions> = {}): Plugin {
+export default function externals(options: ExternalsOptions = {}): Plugin {
 
     // Store eventual warnings until we can display them
     const warnings: string[] = []
 
     // Consolidate options
-    const opts: ExternalsOptions = {
+    const opts: Required<ExternalsOptions> = {
         packagePath: resolve(process.cwd(), 'package.json'),
         builtins: true,
         deps: false,
@@ -56,7 +64,9 @@ export default function externals(options: Partial<ExternalsOptions> = {}): Plug
                 return new RegExp('^' + entry.replace(/[.*+?^${}()|[\]\\]/g, '\\$&') + '$')
             }
             else {
-                warnings.push(`Ignoring wrong entry type #${index} in '${option}' option: '${entry}'`)
+                if (!!entry) {
+                    warnings.push(`Ignoring wrong entry type #${index} in '${option}' option: '${entry}'`)
+                }
                 return /(?=no)match/
             }
         })

src/index.ts

@@ -18,7 +18,7 @@
         "importHelpers": false,
         "noEmitHelpers": false,
         "alwaysStrict": true,
-        "removeComments": true,
+        "removeComments": false,
         "declaration": false,
         // "module": "esnext",             // overriden by rollup-plugin-ts
         // "outDir": "out",                // overriden by rollup-plugin-ts