chore: implement handle trailing slash

Author: openscript

gatsby-node.ts

@@ -19,6 +19,7 @@ export const pluginOptionsSchema: GatsbyNode['pluginOptionsSchema'] = ({ Joi })
         }),
       ),
     pathBlacklist: Joi.array().description('Omit certain path segments'),
+    trailingSlash: Joi.string().valid('always', 'never', 'ignore').default('always'),
   });
 };
 

src/utils/__snapshots__/path.test.ts.snap

@@ -0,0 +1,15 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`translatePagePaths generatePageContextByPath should default to empty prefix 1`] = `
+{
+  "locale": undefined,
+  "prefix": undefined,
+}
+`;
+
+exports[`translatePagePaths generatePageContextByPath should generate the page context by path 1`] = `
+{
+  "locale": "en-US",
+  "prefix": "en",
+}
+`;

src/utils/path.test.ts

@@ -1,5 +1,62 @@
 import { PluginOptions } from 'gatsby';
-import { addLocalePrefix, parsePathPrefix, translatePagePaths, trimRightSlash, trimSlashes } from './path';
+import {
+  addLocalePrefix,
+  generatePageContextByPath,
+  handleTrailingSlash,
+  parsePathPrefix,
+  translatePagePaths,
+  trimRightSlash,
+  trimSlashes,
+} from './path';
+
+describe('handleTrailingSlash', () => {
+  it('should leave trailing slahes, when the option is set to always', () => {
+    const expectation = handleTrailingSlash('https://example.com/', 'always');
+    expect(expectation).toBe('https://example.com/');
+  });
+
+  it('should add trailing slahes, when the option is set to always', () => {
+    const expectation = handleTrailingSlash('https://example.com', 'always');
+    expect(expectation).toBe('https://example.com/');
+  });
+
+  it('should remove trailing slahes, when the option is set to never', () => {
+    const expectation = handleTrailingSlash('https://example.com/', 'never');
+    expect(expectation).toBe('https://example.com');
+  });
+
+  it('should not add trailing slahes, when the option is set to never', () => {
+    const expectation = handleTrailingSlash('https://example.com', 'never');
+    expect(expectation).toBe('https://example.com');
+  });
+
+  it('should return root paths', () => {
+    const expectation = handleTrailingSlash('/', 'never');
+    expect(expectation).toBe('/');
+  });
+
+  it('should return empty paths', () => {
+    const expectation = handleTrailingSlash('', 'never');
+    expect(expectation).toBe('');
+  });
+
+  it('should return empty paths', () => {
+    const expectation = handleTrailingSlash('', 'never');
+    expect(expectation).toBe('');
+  });
+
+  it('should return paths, when the option is set to ignore', () => {
+    let expectation = handleTrailingSlash('https://example.com', 'ignore');
+    expect(expectation).toBe('https://example.com');
+    expectation = handleTrailingSlash('https://example.com/', 'ignore');
+    expect(expectation).toBe('https://example.com/');
+  });
+
+  it('should default to always', () => {
+    const expectation = handleTrailingSlash('https://example.com');
+    expect(expectation).toBe('https://example.com/');
+  });
+});
 
 describe('trimRightSlash', () => {
   it('should trim the right slash', () => {
@@ -103,4 +160,46 @@ describe('translatePagePaths', () => {
       { locale: 'zh-CN', path: '/zh/imprint' },
     ]);
   });
+
+  describe('generatePageContextByPath', () => {
+    const path = '/imprint';
+    const options: PluginOptions = {
+      defaultLocale: `en-US`,
+      siteUrl: '',
+      locales: [
+        {
+          locale: `en-US`,
+          prefix: `en`,
+          slugs: {},
+          messages: {},
+        },
+        {
+          locale: `de-CH`,
+          prefix: `de`,
+          slugs: {
+            '/imprint': '/impressum',
+          },
+          messages: {},
+        },
+        {
+          locale: `zh-CN`,
+          prefix: `zh`,
+          slugs: {},
+          messages: {},
+        },
+      ],
+      plugins: [],
+    };
+
+    it('should generate the page context by path', () => {
+      const expectation = generatePageContextByPath(path, options);
+      expect(expectation).toMatchSnapshot();
+    });
+
+    it('should default to empty prefix', () => {
+      const customOptions = { ...options, defaultLocale: 'fr-FR' };
+      const expectation = generatePageContextByPath(path, customOptions);
+      expect(expectation).toMatchSnapshot();
+    });
+  });
 });

src/utils/path.ts

@@ -1,6 +1,23 @@
 import { posix as nodePath } from 'path';
 import { PluginOptions } from 'gatsby';
 
+export const handleTrailingSlash = (path: string, trailingSlashOption: PluginOptions['trailingSlash'] = 'always') => {
+  if (path === '/' || path.length < 1) {
+    return path;
+  }
+
+  const hasTrailingSlash = path.endsWith('/');
+
+  switch (trailingSlashOption) {
+    case 'always':
+      return hasTrailingSlash ? path : `${path}/`;
+    case 'never':
+      return hasTrailingSlash ? path.slice(0, -1) : path;
+    default:
+      return path;
+  }
+};
+
 export const trimRightSlash = (path: string) => {
   return path === '/' ? path : path.replace(/\/$/, '');
 };

types.d.ts

@@ -39,5 +39,6 @@ declare module 'gatsby' {
       pageBlacklist?: string[];
     }[];
     pathBlacklist?: string[];
+    trailingSlash?: 'always' | 'never' | 'ignore';
   }
 }