feat(utils): add isChildPath util

packages/@vuepress/utils/__tests__/isChildPath.spec.ts

@@ -0,0 +1,32 @@
+import { isChildPath } from '@vuepress/utils'
+
+const testCases: [[string, string], boolean][] = [
+  [['/foo', '/foo'], true],
+  [['/foo', '/bar'], false],
+  [['/foo', '/foo/bar'], false],
+  [['/foo/bar', '/foo'], true],
+  [['/foo', '/foo-bar'], false],
+  [['/foo-bar', '/foo'], false],
+  [['C:\\foo', 'C:\\foo'], true],
+  [['C:\\foo', 'C:\\bar'], false],
+  [['C:\\foo', 'C:\\foo\\bar'], false],
+  [['C:\\foo\\bar', 'C:\\foo'], true],
+  [['C:\\foo', 'C:\\foo-bar'], false],
+  [['C:\\foo-bar', 'C:\\foo'], false],
+  [['foo', 'foo'], false],
+  [['foo', 'bar'], false],
+  [['foo', 'foo/bar'], false],
+  [['foo/bar', 'foo'], false],
+  [['foo', 'foo-bar'], false],
+  [['foo-bar', 'foo'], false],
+]
+
+describe('utils > isChildPath', () => {
+  describe('should check child path correctly', () => {
+    testCases.forEach(([source, expected]) => {
+      it(JSON.stringify(source), () => {
+        expect(isChildPath(...source)).toBe(expected)
+      })
+    })
+  })
+})

packages/@vuepress/utils/src/index.ts

@@ -9,6 +9,7 @@ export * as path from 'upath'
 
 export * from './hasExportDefault'
 export * from './hash'
+export * from './isChildPath'
 export * from './logger'
 export * from './renderHead'
 export * from './renderHeadAttrs'

packages/@vuepress/utils/src/isChildPath.ts

@@ -0,0 +1,16 @@
+import * as path from 'upath'
+
+/**
+ * Check if `child` is a sub path of `parent` or not. Return `true` if
+ * they are the same path
+ */
+export const isChildPath = (child: string, parent: string): boolean => {
+  const childPath = path.normalize(child)
+  const parentPath = path.normalize(parent)
+  // path.win32.isAbsolute could check both win32 and posix absolute path correctly
+  if (!path.win32.isAbsolute(childPath) || !path.win32.isAbsolute(parentPath)) {
+    return false
+  }
+  const relativePath = path.relative(parentPath, childPath)
+  return relativePath === '' || !relativePath.startsWith('..')
+}