feat: extToValue

Signed-off-by: Lexus Drumgold <unicornware@flexdevelopment.llc>

Author: unicornware

README.md

@@ -92,6 +92,7 @@ import {
   delimiter,
   dirname,
   dot,
+  extToValue,
   extname,
   fileURLToPath,
   format,
@@ -128,6 +129,7 @@ This package exports the following identifiers:
 - [`delimiter`](./src/lib/delimiter.mts)
 - [`dirname`](./src/lib/dirname.mts)
 - [`dot`](./src/lib/dot.mts)
+- [`extToValue`](./src/lib/ext-to-value.mts)
 - [`extname`](./src/lib/extname.mts)
 - [`extnames`](./src/lib/extnames.mts)
 - [`fileURLToPath`](./src/lib/file-url-to-path.mts)

src/__snapshots__/index.e2e.snap

@@ -9,6 +9,7 @@ exports[`e2e:pathe > should expose public api 1`] = `
   "delimiter",
   "dirname",
   "dot",
+  "extToValue",
   "extname",
   "extnames",
   "fileURLToPath",

src/interfaces/pathe.mts

@@ -156,6 +156,34 @@ interface Pathe extends PosixPlatformPath {
    */
   readonly dot: Dot
 
+  /**
+   * Get a value for `input` based on its file extension.
+   *
+   * This algorithm picks the value with the longest matching file extension,
+   * so if `map` has the keys `'.mts'` and `'.d.mts'`, the value for `'.d.mts'`
+   * will be returned.
+   *
+   * @see {@linkcode EmptyString}
+   * @see {@linkcode Ext}
+   *
+   * @template {any} T
+   *  Map value
+   *
+   * @this {void}
+   *
+   * @param {URL | string} input
+   *  The {@linkcode URL}, URL string, or path to handle
+   * @param {Partial<Record<EmptyString | Ext, T>>} map
+   *  Extension map
+   * @return {T | undefined}
+   *  Value for `input` or `undefined`
+   */
+  extToValue<T>(
+    this: void,
+    input: URL | string,
+    map: Partial<Record<EmptyString | Ext, T>>
+  ): T | undefined
+
   /**
    * Get a list of file extensions for `input`.
    *

src/lib/__tests__/ext-to-value.spec.mts

@@ -0,0 +1,32 @@
+/**
+ * @file Unit Tests - extToValue
+ * @module pathe/lib/tests/unit/extToValue
+ */
+
+import changeExt from '#lib/change-ext'
+import testSubject from '#lib/ext-to-value'
+import pathToFileURL from '#lib/path-to-file-url'
+import removeExt from '#lib/remove-ext'
+import type { EmptyString, Ext } from '@flex-development/pathe'
+import type { Loader } from 'esbuild'
+
+describe('unit:lib/extToValue', () => {
+  let map: Record<EmptyString | Ext, Loader>
+
+  beforeAll(() => {
+    map = { '': 'ts', '.d.mts': 'copy', '.mts': 'ts', '.npmrc': 'copy' }
+  })
+
+  it.each<[URL | string, Loader | undefined]>([
+    ['.npmrc', 'copy'],
+    [changeExt(import.meta.url, 'cts'), undefined],
+    [import.meta.url, 'ts'],
+    [pathToFileURL('dist/lib/ext-to-value.d.mts'), 'copy'],
+    [removeExt(import.meta.url, 'spec.mts'), 'ts']
+  ])('should return value based on file extension of `input` (%#)', (
+    input,
+    expected
+  ) => {
+    expect(testSubject(input, map)).to.eq(expected)
+  })
+})

src/lib/ext-to-value.mts

@@ -0,0 +1,90 @@
+/**
+ * @file extToValue
+ * @module pathe/lib/extToValue
+ */
+
+import basename from '#lib/basename'
+import dot from '#lib/dot'
+import type { EmptyString, Ext } from '@flex-development/pathe'
+
+/**
+ * Get a value for `input` based on its file extension.
+ *
+ * This algorithm picks the value with the longest matching file extension,
+ * so if `map` has the keys `'.mts'` and `'.d.mts'`, the value for `'.d.mts'`
+ * will be returned.
+ *
+ * @see {@linkcode EmptyString}
+ * @see {@linkcode Ext}
+ *
+ * @category
+ *  utils
+ *
+ * @template {any} T
+ *  Map value
+ *
+ * @this {void}
+ *
+ * @param {URL | string} input
+ *  The {@linkcode URL}, URL string, or path to handle
+ * @param {Partial<Record<EmptyString | Ext, T>>} map
+ *  Extension map
+ * @return {T | undefined}
+ *  Value based on file extension of `input`
+ */
+function extToValue<T>(
+  this: void,
+  input: URL | string,
+  map: Partial<Record<EmptyString | Ext, T>>
+): T | undefined {
+  /**
+   * Basename to check.
+   *
+   * @var {string} base
+   */
+  let base: string = basename(input)
+
+  /**
+   * Index of {@linkcode dot}.
+   *
+   * @var {number} index
+   */
+  let index: number = base.indexOf(dot)
+
+  /**
+   * Current value.
+   *
+   * @var {T | undefined} value
+   */
+  let value: T | undefined
+
+  if (index === -1) {
+    value = map['']
+  } else {
+    while (true) {
+      value = map[base.slice(index) as EmptyString | Ext]
+
+      if (value === undefined) {
+        base = base.slice(index + 1)
+
+        /**
+         * Next index of {@linkcode dot}.
+         *
+         * @const {number} nextIndex
+         */
+        const nextIndex: number = base.indexOf(dot)
+
+        if (nextIndex !== -1) {
+          index = nextIndex
+          continue
+        }
+      }
+
+      break
+    }
+  }
+
+  return value
+}
+
+export default extToValue

src/lib/index.mts

@@ -10,6 +10,7 @@ export { default as cwd } from '#lib/cwd'
 export { default as delimiter } from '#lib/delimiter'
 export { default as dirname } from '#lib/dirname'
 export { default as dot } from '#lib/dot'
+export { default as extToValue } from '#lib/ext-to-value'
 export { default as extname } from '#lib/extname'
 export { default as extnames } from '#lib/extnames'
 export { default as fileURLToPath } from '#lib/file-url-to-path'

src/pathe.mts

@@ -12,6 +12,7 @@ import {
   delimiter,
   dirname,
   dot,
+  extToValue,
   extname,
   extnames,
   fileURLToPath,
@@ -113,6 +114,7 @@ const pathe: Pathe = {
   delimiter,
   dirname,
   dot,
+  extToValue,
   extname,
   extnames,
   fileURLToPath,