refactor(utils): remove duplicated function (#9972)

Co-authored-by: sebastien <lorber.sebastien@gmail.com>

packages/docusaurus-utils-common/src/__tests__/applyTrailingSlash.test.ts

@@ -6,7 +6,10 @@
  */
 
 import applyTrailingSlash, {
+  addTrailingSlash,
   type ApplyTrailingSlashParams,
+  addLeadingSlash,
+  removeTrailingSlash,
 } from '../applyTrailingSlash';
 
 function params(
@@ -176,3 +179,30 @@ describe('applyTrailingSlash', () => {
     ).toBe('https://xyz.com/abc/?search#anchor');
   });
 });
+
+describe('addTrailingSlash', () => {
+  it('is no-op for path with trailing slash', () => {
+    expect(addTrailingSlash('/abcd/')).toBe('/abcd/');
+  });
+  it('adds / for path without trailing slash', () => {
+    expect(addTrailingSlash('/abcd')).toBe('/abcd/');
+  });
+});
+
+describe('addLeadingSlash', () => {
+  it('is no-op for path with leading slash', () => {
+    expect(addLeadingSlash('/abc')).toBe('/abc');
+  });
+  it('adds / for path without leading slash', () => {
+    expect(addLeadingSlash('abc')).toBe('/abc');
+  });
+});
+
+describe('removeTrailingSlash', () => {
+  it('is no-op for path without trailing slash', () => {
+    expect(removeTrailingSlash('/abcd')).toBe('/abcd');
+  });
+  it('removes / for path with trailing slash', () => {
+    expect(removeTrailingSlash('/abcd/')).toBe('/abcd');
+  });
+});

packages/docusaurus-utils-common/src/__tests__/stringUtils.test.ts

@@ -0,0 +1,55 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {addPrefix, addSuffix, removePrefix, removeSuffix} from '../stringUtils';
+
+describe('removePrefix', () => {
+  it("is no-op when prefix doesn't exist", () => {
+    expect(removePrefix('abcdef', 'ijk')).toBe('abcdef');
+    expect(removePrefix('abcdef', 'def')).toBe('abcdef');
+    expect(removePrefix('abcdef', '')).toBe('abcdef');
+  });
+  it('removes prefix', () => {
+    expect(removePrefix('prefix', 'pre')).toBe('fix');
+  });
+});
+
+describe('removeSuffix', () => {
+  it("is no-op when suffix doesn't exist", () => {
+    expect(removeSuffix('abcdef', 'ijk')).toBe('abcdef');
+    expect(removeSuffix('abcdef', 'abc')).toBe('abcdef');
+    expect(removeSuffix('abcdef', '')).toBe('abcdef');
+  });
+  it('removes suffix', () => {
+    expect(removeSuffix('abcdef', 'ef')).toBe('abcd');
+  });
+  it('removes empty suffix', () => {
+    expect(removeSuffix('abcdef', '')).toBe('abcdef');
+  });
+});
+
+describe('addPrefix', () => {
+  it('is no-op when prefix already exists', () => {
+    expect(addPrefix('abcdef', 'abc')).toBe('abcdef');
+    expect(addPrefix('abc', '')).toBe('abc');
+    expect(addPrefix('', '')).toBe('');
+  });
+  it('adds prefix', () => {
+    expect(addPrefix('def', 'abc')).toBe('abcdef');
+  });
+});
+
+describe('addSuffix', () => {
+  it('is no-op when suffix already exists', () => {
+    expect(addSuffix('abcdef', 'def')).toBe('abcdef');
+    expect(addSuffix('abc', '')).toBe('abc');
+    expect(addSuffix('', '')).toBe('');
+  });
+  it('adds suffix', () => {
+    expect(addSuffix('abc', 'def')).toBe('abcdef');
+  });
+});

packages/docusaurus-utils-common/src/applyTrailingSlash.ts

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {addPrefix, removeSuffix} from './stringUtils';
 import type {DocusaurusConfig} from '@docusaurus/types';
 
 export type ApplyTrailingSlashParams = Pick<
@@ -12,6 +13,10 @@ export type ApplyTrailingSlashParams = Pick<
   'trailingSlash' | 'baseUrl'
 >;
 
+export function addTrailingSlash(str: string): string {
+  return str.endsWith('/') ? str : `${str}/`;
+}
+
 // Trailing slash handling depends in some site configuration options
 export default function applyTrailingSlash(
   path: string,
@@ -24,13 +29,6 @@ export default function applyTrailingSlash(
     return path;
   }
 
-  // TODO deduplicate: also present in @docusaurus/utils
-  function addTrailingSlash(str: string): string {
-    return str.endsWith('/') ? str : `${str}/`;
-  }
-  function removeTrailingSlash(str: string): string {
-    return str.endsWith('/') ? str.slice(0, -1) : str;
-  }
   function handleTrailingSlash(str: string, trailing: boolean): string {
     return trailing ? addTrailingSlash(str) : removeTrailingSlash(str);
   }
@@ -55,3 +53,13 @@ export default function applyTrailingSlash(
 
   return path.replace(pathname, newPathname);
 }
+
+/** Appends a leading slash to `str`, if one doesn't exist. */
+export function addLeadingSlash(str: string): string {
+  return addPrefix(str, '/');
+}
+
+/** Removes the trailing slash from `str`. */
+export function removeTrailingSlash(str: string): string {
+  return removeSuffix(str, '/');
+}

packages/docusaurus-utils-common/src/index.ts

@@ -11,6 +11,10 @@ export const blogPostContainerID = '__blog-post-container';
 
 export {
   default as applyTrailingSlash,
+  addTrailingSlash,
+  addLeadingSlash,
+  removeTrailingSlash,
   type ApplyTrailingSlashParams,
 } from './applyTrailingSlash';
+export {addPrefix, removeSuffix, addSuffix, removePrefix} from './stringUtils';
 export {getErrorCausalChain} from './errorUtils';

packages/docusaurus-utils-common/src/stringUtils.ts

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/** Adds a given string prefix to `str`. */
+export function addPrefix(str: string, prefix: string): string {
+  return str.startsWith(prefix) ? str : `${prefix}${str}`;
+}
+
+/** Removes a given string suffix from `str`. */
+export function removeSuffix(str: string, suffix: string): string {
+  if (suffix === '') {
+    // str.slice(0, 0) is ""
+    return str;
+  }
+  return str.endsWith(suffix) ? str.slice(0, -suffix.length) : str;
+}
+
+/** Adds a given string suffix to `str`. */
+export function addSuffix(str: string, suffix: string): string {
+  return str.endsWith(suffix) ? str : `${str}${suffix}`;
+}
+
+/** Removes a given string prefix from `str`. */
+export function removePrefix(str: string, prefix: string): string {
+  return str.startsWith(prefix) ? str.slice(prefix.length) : str;
+}