🐛 Fix computing relative URIs (#1177)

packages/core/src/service/CacheService.ts

@@ -182,7 +182,7 @@ export class CacheService {
 		}
 
 		for (const [uri, checksum] of Object.entries(this.checksums.files)) {
-			if (unchangedRoots.some((root) => uri.startsWith(root))) {
+			if (unchangedRoots.some((root) => fileUtil.isSubUriOf(uri, root))) {
 				ans.unchangedFiles.push(uri)
 				continue
 			}

packages/core/src/service/fileUtil.ts

@@ -6,6 +6,46 @@ export type RootUriString = `${string}/`
 export type FileExtension = `.${string}`
 
 export namespace fileUtil {
+	/**
+	 * Get the relative URI of `target` based from `base`.
+	 *
+	 * @returns The relative URI, or `undefined` if `target` is not under `base`.
+	 */
+	export function getRelativeUriFromBase(
+		target: string,
+		base: string,
+	): string | undefined {
+		const baseUri = new Uri(base)
+		const targetUri = new Uri(target)
+
+		if (baseUri.origin !== targetUri.origin) {
+			// Different scheme, hostname, and/or port
+			return undefined
+		}
+
+		const baseComponents = baseUri.pathname.split('/')
+			.filter((v) => !!v)
+		const targetComponents = targetUri.pathname.split('/')
+			.filter((v) => !!v)
+
+		if (
+			baseComponents.length > targetComponents.length ||
+			baseComponents.some((bc, i) =>
+				decodeURIComponent(bc) !== decodeURIComponent(targetComponents[i])
+			)
+		) {
+			return undefined
+		}
+
+		return targetComponents.slice(baseComponents.length).map(
+			encodeURIComponent,
+		).join('/')
+	}
+
+	export function isSubUriOf(uri: string, base: string): boolean {
+		return getRelativeUriFromBase(uri, base) !== undefined
+	}
+
 	/**
 	 * @param rootUris The root URIs. Each URI in this array must end with a slash (`/`).
 	 * @param uri The target file URI.
@@ -25,8 +65,9 @@ export namespace fileUtil {
 		rootUris: readonly RootUriString[],
 	): Generator<string, undefined, unknown> {
 		for (const root of rootUris) {
-			if (uri.startsWith(root)) {
-				yield decodeURIComponent(uri.slice(root.length))
+			const rel = getRelativeUriFromBase(uri, root)
+			if (rel !== undefined) {
+				yield rel
 			}
 		}
 		return undefined

packages/core/test/service/fileUtil.spec.ts

@@ -3,6 +3,56 @@ import { describe, it } from 'mocha'
 import { fileUtil } from '../../lib/index.js'
 
 describe('fileUtil', () => {
+	describe('getRelativeUriFromBase()', () => {
+		const bases: string[] = [
+			'file:///c%3A/Users/admin/',
+			'file:///c:/Users/admin/',
+		]
+		const suites: { uri: string; expected: string | undefined }[] = [
+			{ uri: 'file:///c%3A/Users/admin/', expected: '' },
+			{ uri: 'file:///c%3A/Users/admin/foo.mcdoc', expected: 'foo.mcdoc' },
+			{
+				uri: 'file:///c%3A/Users/admin/foo/bar.mcdoc',
+				expected: 'foo/bar.mcdoc',
+			},
+			{ uri: 'file:///c:/Users/admin/', expected: '' },
+			{ uri: 'file:///c:/Users/admin/foo.mcdoc', expected: 'foo.mcdoc' },
+			{
+				// Should treat multiple slashes in a row in pathname as a single slash.
+				uri: 'file:///c://///Users///admin//foo.mcdoc',
+				expected: 'foo.mcdoc',
+			},
+			{
+				uri: 'file:///c:/Users/admin/foo/bar.mcdoc',
+				expected: 'foo/bar.mcdoc',
+			},
+			{ uri: 'file:///qux.mcdoc', expected: undefined },
+		]
+		for (const { uri, expected } of suites) {
+			for (const base of bases) {
+				it(`Should return '${expected}' for '${uri}' when base is '${base}'`, () => {
+					assert.strictEqual(
+						fileUtil.getRelativeUriFromBase(uri, base),
+						expected,
+					)
+				})
+			}
+		}
+	})
+	describe('isSubUriOf()', () => {
+		const root: string = 'file:///c%3A/Users/admin/'
+		const suites: { uri: string; expected: boolean }[] = [
+			{ uri: 'file:///c%3A/Users/admin/', expected: true },
+			{ uri: 'file:///c%3A/Users/admin/foo.mcdoc', expected: true },
+			{ uri: 'file:///c:/Users/admin/foo.mcdoc', expected: true },
+			{ uri: 'file:///qux.mcdoc', expected: false },
+		]
+		for (const { uri, expected } of suites) {
+			it(`Should return '${expected}' for '${uri}'`, () => {
+				assert.strictEqual(fileUtil.isSubUriOf(uri, root), expected)
+			})
+		}
+	})
 	describe('getRel()', () => {
 		const rootUris: `${string}/`[] = [
 			'file:///root1/subdir/',