Add opt-in Unicode NFC path identity for CouchDB

src/apps/cli/adapters/NodeFileSystemAdapter.ts

@@ -3,7 +3,7 @@ import type { IFileSystemAdapter } from "@vrtmrz/livesync-commonlib/compat/servi
 import { NodePathAdapter } from "./NodePathAdapter";
 import { NodeTypeGuardAdapter } from "./NodeTypeGuardAdapter";
 import { NodeConversionAdapter } from "./NodeConversionAdapter";
-import { NodeStorageAdapter } from "@vrtmrz/livesync-commonlib/node";
+import { AmbiguousNormalisedPathError, UnicodeResolvingNodeStorageAdapter } from "./UnicodeResolvingNodeStorageAdapter";
 import { NodeVaultAdapter } from "./NodeVaultAdapter";
 import type { NodeFile, NodeFolder, NodeStat } from "./NodeTypes";
 import { path } from "@vrtmrz/livesync-commonlib/node";
@@ -16,19 +16,21 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
     readonly path: NodePathAdapter;
     readonly typeGuard: NodeTypeGuardAdapter;
     readonly conversion: NodeConversionAdapter;
-    readonly storage: NodeStorageAdapter;
+    readonly storage: UnicodeResolvingNodeStorageAdapter;
     readonly vault: NodeVaultAdapter;
 
     private fileCache = new Map<string, NodeFile>();
 
     constructor(
         private basePath: string,
-        private reportDiagnostic: CliDiagnosticReporter = () => undefined
+        private reportDiagnostic: CliDiagnosticReporter = () => undefined,
+        getPathNormalizationVersion: () => number = () => 0,
+        isCaseInsensitive: () => boolean = () => false
     ) {
         this.path = new NodePathAdapter();
         this.typeGuard = new NodeTypeGuardAdapter();
         this.conversion = new NodeConversionAdapter();
-        this.storage = new NodeStorageAdapter(basePath);
+        this.storage = new UnicodeResolvingNodeStorageAdapter(basePath, getPathNormalizationVersion, isCaseInsensitive);
         this.vault = new NodeVaultAdapter(this.storage);
     }
 
@@ -58,6 +60,14 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
 
     async getAbstractFileByPath(p: FilePath | string): Promise<NodeFile | null> {
         const pathStr = this.normalisePath(p);
+        if (this.storage.isUnicodePathNormalizationEnabled) {
+            const resolvedPath = await this.storage.resolveLogicalPath(pathStr, false, false);
+            if (resolvedPath === null) {
+                this.fileCache.delete(pathStr);
+                return null;
+            }
+            return await this.refreshResolvedFile(resolvedPath);
+        }
         if (!this.fileCache.has(pathStr) && !(await this.hasExactPathCase(pathStr))) {
             this.fileCache.delete(pathStr);
             return null;
@@ -68,6 +78,15 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
     async getAbstractFileByPathInsensitive(p: FilePath | string): Promise<NodeFile | null> {
         const pathStr = this.normalisePath(p);
 
+        if (this.storage.isUnicodePathNormalizationEnabled) {
+            const resolvedPath = await this.storage.resolveLogicalPath(pathStr, true, false);
+            if (resolvedPath === null) {
+                this.fileCache.delete(pathStr);
+                return null;
+            }
+            return await this.refreshResolvedFile(resolvedPath);
+        }
+
         const exact = await this.getAbstractFileByPath(pathStr);
         if (exact) {
             return exact;
@@ -115,17 +134,34 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
         // This is used by Obsidian to sync internal file metadata
     }
 
-    async refreshFile(p: string): Promise<NodeFile | null> {
+    async refreshFile(p: string, caseInsensitive = false): Promise<NodeFile | null> {
         const pathStr = this.normalisePath(p);
         try {
-            const stat = await this.storage.stat(pathStr);
-            if (stat?.type !== "file") {
+            const resolvedPath = this.storage.isUnicodePathNormalizationEnabled
+                ? await this.storage.resolveLogicalPath(pathStr, caseInsensitive, false)
+                : pathStr;
+            if (resolvedPath === null) {
                 this.fileCache.delete(pathStr);
                 return null;
             }
+            return await this.refreshResolvedFile(resolvedPath);
+        } catch (error) {
+            if (error instanceof AmbiguousNormalisedPathError) throw error;
+            this.fileCache.delete(pathStr);
+            return null;
+        }
+    }
+
+    private async refreshResolvedFile(resolvedPath: string): Promise<NodeFile | null> {
+        try {
+            const stat = await this.storage.statExact(resolvedPath);
+            if (stat?.type !== "file") {
+                this.fileCache.delete(resolvedPath);
+                return null;
+            }
 
             const file: NodeFile = {
-                path: pathStr as FilePath,
+                path: resolvedPath as FilePath,
                 stat: {
                     size: stat.size,
                     mtime: stat.mtime,
@@ -133,11 +169,12 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
                     type: "file",
                 },
             };
-            this.fileCache.set(pathStr, file);
+            this.fileCache.set(resolvedPath, file);
             return file;
-        } catch {
+        } catch (error) {
+            if (error instanceof AmbiguousNormalisedPathError) throw error;
             // Evict so a deleted file is not returned by subsequent cache scans.
-            this.fileCache.delete(pathStr);
+            this.fileCache.delete(resolvedPath);
             return null;
         }
     }
@@ -146,18 +183,21 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
      * Helper method to recursively scan directory and populate file cache
      */
     async scanDirectory(relativePath: string = ""): Promise<void> {
-        await this.scanDirectoryInto(relativePath, this.fileCache);
+        const resolvedPath = await this.storage.resolveLogicalPath(relativePath, false, false);
+        if (resolvedPath !== null) await this.scanDirectoryInto(resolvedPath, this.fileCache);
     }
 
     private async scanDirectoryInto(relativePath: string, files: Map<string, NodeFile>): Promise<void> {
         const fullPath = this.resolvePath(relativePath);
         try {
-            const directoryStat = await this.storage.stat(relativePath);
+            const directoryStat = this.storage.isUnicodePathNormalizationEnabled
+                ? await this.storage.statExact(relativePath)
+                : await this.storage.stat(relativePath, false);
             if (directoryStat?.type !== "folder") throw new Error(`Directory does not exist: ${fullPath}`);
-            const entries = await this.storage.list(relativePath);
+            const entries = await this.storage.listExact(relativePath);
 
             for (const entryPath of entries.files) {
-                const stat = await this.storage.stat(entryPath);
+                const stat = await this.storage.statExact(entryPath);
                 if (stat?.type !== "file") continue;
                 const file: NodeFile = {
                     path: entryPath as FilePath,
@@ -169,6 +209,7 @@ export class NodeFileSystemAdapter implements IFileSystemAdapter<NodeFile, NodeF
                 await this.scanDirectoryInto(entryPath, files);
             }
         } catch (error) {
+            if (error instanceof AmbiguousNormalisedPathError) throw error;
             // Directory doesn't exist or is not readable
             this.reportDiagnostic(`Error scanning directory ${fullPath}:`, error);
         }

src/apps/cli/adapters/NodeFileSystemAdapter.unit.spec.ts

@@ -1,5 +1,12 @@
 import { afterEach, describe, expect, it, vi } from "vitest";
-import { fsPromises as fs, os, path } from "@vrtmrz/livesync-commonlib/node";
+import { fsPromises as fs, NodeStorageAdapter, os, path } from "@vrtmrz/livesync-commonlib/node";
+import { DEFAULT_SETTINGS, type FilePath } from "@vrtmrz/livesync-commonlib/compat/common/types";
+import {
+    ServiceRebuilder,
+    type ServiceRebuilderDependencies,
+} from "@vrtmrz/livesync-commonlib/compat/serviceModules/Rebuilder";
+import { PathServiceCompat } from "@vrtmrz/livesync-commonlib/compat/services/implements/injectable/InjectablePathService";
+import { ServiceContext } from "@vrtmrz/livesync-commonlib/compat/services/base/ServiceBase";
 import { NodeFileSystemAdapter } from "./NodeFileSystemAdapter";
 
 describe("NodeFileSystemAdapter file enumeration", () => {
@@ -116,3 +123,382 @@ describe("NodeFileSystemAdapter file enumeration", () => {
         await expect(adapter.getFiles()).resolves.toEqual([]);
     });
 });
+
+describe("NodeFileSystemAdapter Unicode path resolution", () => {
+    const tempDirs: string[] = [];
+
+    async function createVault() {
+        const directory = await fs.mkdtemp(path.join(os.tmpdir(), "livesync-cli-unicode-"));
+        tempDirs.push(directory);
+        return directory;
+    }
+
+    function createNormalisingAdapter(directory: string, caseInsensitive = false) {
+        return new NodeFileSystemAdapter(
+            directory,
+            undefined,
+            () => 1,
+            () => caseInsensitive
+        );
+    }
+
+    afterEach(async () => {
+        await Promise.all(tempDirs.splice(0).map((directory) => fs.rm(directory, { recursive: true, force: true })));
+    });
+
+    it.each([0, 1])("keeps an NFD-only file in the storage listing in identity mode %s", async (version) => {
+        const directory = await createVault();
+        const originalPath = "café.md".normalize("NFD");
+        await fs.writeFile(path.join(directory, originalPath), "original");
+        const report = vi.fn();
+        const adapter = new NodeFileSystemAdapter(directory, report, () => version);
+
+        expect((await adapter.getFiles()).map((file) => file.path)).toEqual([originalPath]);
+        expect(report).not.toHaveBeenCalled();
+        await expect(fs.readFile(path.join(directory, originalPath), "utf8")).resolves.toBe("original");
+        expect(await fs.readdir(directory)).toEqual([originalPath]);
+    });
+
+    it.each([false, true])(
+        "enumerates nested mixed names once per directory with case-insensitive matching %s",
+        async (caseInsensitive) => {
+            const directory = await createVault();
+            const parent = "café".normalize("NFD");
+            const child = `${parent}/Étage`;
+            await fs.mkdir(path.join(directory, child), { recursive: true });
+            const names = Array.from(
+                { length: 12 },
+                (_, index) =>
+                    `${child}/${index}-résumé.md`
+                        .normalize(index % 2 ? "NFC" : "NFD")
+                        .split("/")
+                        .pop()!
+            );
+            for (const name of names) await fs.writeFile(path.join(directory, child, name), "content");
+            const adapter = createNormalisingAdapter(directory, caseInsensitive);
+            const list = vi.spyOn(NodeStorageAdapter.prototype, "list");
+            try {
+                const files = await adapter.getFiles();
+                expect(files.map((file) => file.path).sort()).toEqual(names.map((name) => `${child}/${name}`).sort());
+                expect(list).toHaveBeenCalledTimes(3);
+            } finally {
+                list.mockRestore();
+            }
+        }
+    );
+
+    it("uses the existing mixed parent during directory preparation and preserves the new leaf spelling", async () => {
+        const directory = await createVault();
+        const parent = "café".normalize("NFD");
+        const child = `${parent}/Étage`;
+        await fs.mkdir(path.join(directory, child), { recursive: true });
+        const adapter = createNormalisingAdapter(directory);
+        await adapter.storage.mkdir("café");
+        await adapter.storage.mkdir("café/Étage");
+        const newName = "résumé.md".normalize("NFD");
+        const file = await adapter.vault.create(`café/Étage/${newName}`, "created");
+
+        expect(file.path).toBe(`${child}/${newName}`);
+        expect(await fs.readdir(directory)).toEqual([parent]);
+        expect(await fs.readdir(path.join(directory, parent))).toEqual(["Étage"]);
+        expect(await fs.readdir(path.join(directory, child))).toEqual([newName]);
+        await expect(adapter.storage.stat(`café/Étage/${newName.normalize("NFC")}`)).resolves.toMatchObject({
+            size: 7,
+        });
+    });
+
+    it("rejects an NFC-equivalent file and directory before scanning or writing a child", async () => {
+        const directory = await createVault();
+        const composed = "café";
+        const decomposed = composed.normalize("NFD");
+        await fs.writeFile(path.join(directory, composed), "file");
+        await fs.mkdir(path.join(directory, decomposed));
+        const adapter = createNormalisingAdapter(directory);
+
+        await expect(adapter.getFiles()).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.storage.write(`${composed}/new.md`, "new")).rejects.toThrow(/ambiguous/i);
+        await expect(fs.readFile(path.join(directory, composed), "utf8")).resolves.toBe("file");
+        expect(await fs.readdir(path.join(directory, decomposed))).toEqual([]);
+    });
+
+    it.each([false, true])(
+        "enumerates each directory once for a flat NFC scan with case-insensitive matching %s",
+        async (caseInsensitive) => {
+            const directory = await createVault();
+            for (let index = 0; index < 12; index++) {
+                await fs.writeFile(path.join(directory, `${index}.md`), "content");
+            }
+            const adapter = createNormalisingAdapter(directory, caseInsensitive);
+            const list = vi.spyOn(NodeStorageAdapter.prototype, "list");
+            try {
+                expect(await adapter.getFiles()).toHaveLength(12);
+                expect(list).toHaveBeenCalledTimes(1);
+            } finally {
+                list.mockRestore();
+            }
+        }
+    );
+
+    it("reads, updates, and deletes an NFD file through its NFC path", async () => {
+        const directory = await createVault();
+        const nfcFolder = "café";
+        const nfdFolder = nfcFolder.normalize("NFD");
+        const nfcName = "Ångström.md";
+        const nfdName = nfcName.normalize("NFD");
+        await fs.mkdir(path.join(directory, nfdFolder));
+        await fs.writeFile(path.join(directory, nfdFolder, nfdName), "before", "utf8");
+        const adapter = createNormalisingAdapter(directory);
+
+        const file = await adapter.getAbstractFileByPath(`${nfcFolder}/${nfcName}`);
+        expect(file?.path).toBe(`${nfdFolder}/${nfdName}`);
+        if (!file) throw new Error("Expected the NFC path to resolve to the NFD file");
+        await expect(adapter.vault.read(file)).resolves.toBe("before");
+        await adapter.vault.modify(file, "after");
+        await expect(fs.readFile(path.join(directory, nfdFolder, nfdName), "utf8")).resolves.toBe("after");
+        expect(await fs.readdir(directory)).toEqual([nfdFolder]);
+        expect(await fs.readdir(path.join(directory, nfdFolder))).toEqual([nfdName]);
+
+        await adapter.vault.delete(file);
+
+        await expect(fs.readdir(path.join(directory, nfdFolder))).resolves.toEqual([]);
+    });
+
+    it("creates a new file inside an existing NFD directory using that directory spelling", async () => {
+        const directory = await createVault();
+        const nfdFolder = "café".normalize("NFD");
+        await fs.mkdir(path.join(directory, nfdFolder));
+        const adapter = createNormalisingAdapter(directory);
+
+        const file = await adapter.vault.create("café/new.md", "content");
+
+        expect(file.path).toBe(`${nfdFolder}/new.md`);
+        await expect(fs.readFile(path.join(directory, nfdFolder, "new.md"), "utf8")).resolves.toBe("content");
+        expect(await fs.readdir(directory)).toEqual([nfdFolder]);
+    });
+
+    it("renames a file by case inside an NFD directory while preserving that directory spelling", async () => {
+        const directory = await createVault();
+        const nfcFolder = "Caf\u00e9";
+        const nfdFolder = nfcFolder.normalize("NFD");
+        await fs.mkdir(path.join(directory, nfdFolder));
+        await fs.writeFile(path.join(directory, nfdFolder, "Note.md"), "content", "utf8");
+        const adapter = createNormalisingAdapter(directory, true);
+        const file = await adapter.getAbstractFileByPathInsensitive(`${nfcFolder}/Note.md`);
+        if (!file) throw new Error("Expected the NFC path to resolve to the NFD file");
+
+        const renamedFile = await adapter.renameFile(file, `${nfcFolder}/note.md`);
+
+        expect(renamedFile.path).toBe(`${nfdFolder}/note.md`);
+        expect(await fs.readdir(directory)).toEqual([nfdFolder]);
+        await expect(fs.readdir(path.join(directory, nfdFolder))).resolves.toEqual(["note.md"]);
+        await expect(fs.readFile(path.join(directory, nfdFolder, "note.md"), "utf8")).resolves.toBe("content");
+    });
+
+    it("rejects an NFC/NFD file collision for lookup and vault mutations", async () => {
+        const directory = await createVault();
+        const nfcName = "café.md";
+        const nfdName = nfcName.normalize("NFD");
+        await fs.writeFile(path.join(directory, nfcName), "NFC", "utf8");
+        await fs.writeFile(path.join(directory, nfdName), "NFD", "utf8");
+        const adapter = createNormalisingAdapter(directory);
+        const exactFile = {
+            path: nfcName as FilePath,
+            stat: { ctime: 1, mtime: 2, size: 3, type: "file" as const },
+        };
+
+        await expect(adapter.getAbstractFileByPath(nfcName)).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.vault.modify(exactFile, "changed")).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.vault.delete(exactFile)).rejects.toThrow(/ambiguous/i);
+
+        await expect(fs.readFile(path.join(directory, nfcName), "utf8")).resolves.toBe("NFC");
+        await expect(fs.readFile(path.join(directory, nfdName), "utf8")).resolves.toBe("NFD");
+        expect((await fs.readdir(directory)).sort()).toEqual([nfcName, nfdName].sort());
+    });
+
+    it("rejects an NFC/NFD directory collision before creating a child", async () => {
+        const directory = await createVault();
+        const nfcFolder = "café";
+        const nfdFolder = nfcFolder.normalize("NFD");
+        await fs.mkdir(path.join(directory, nfcFolder));
+        await fs.mkdir(path.join(directory, nfdFolder));
+        await fs.writeFile(path.join(directory, nfcFolder, "inside.md"), "NFC", "utf8");
+        await fs.writeFile(path.join(directory, nfdFolder, "inside.md"), "NFD", "utf8");
+        const adapter = createNormalisingAdapter(directory);
+
+        await expect(adapter.getAbstractFileByPath(`${nfcFolder}/inside.md`)).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.storage.write(`${nfcFolder}/created.md`, "created")).rejects.toThrow(/ambiguous/i);
+
+        await expect(fs.readdir(path.join(directory, nfcFolder))).resolves.toEqual(["inside.md"]);
+        await expect(fs.readdir(path.join(directory, nfdFolder))).resolves.toEqual(["inside.md"]);
+        await expect(fs.readFile(path.join(directory, nfcFolder, "inside.md"), "utf8")).resolves.toBe("NFC");
+        await expect(fs.readFile(path.join(directory, nfdFolder, "inside.md"), "utf8")).resolves.toBe("NFD");
+    });
+
+    it("rejects enumeration when NFC-equivalent directories contain different files", async () => {
+        const directory = await createVault();
+        const nfcFolder = "café";
+        const nfdFolder = nfcFolder.normalize("NFD");
+        await fs.mkdir(path.join(directory, nfcFolder));
+        await fs.mkdir(path.join(directory, nfdFolder));
+        await fs.writeFile(path.join(directory, nfcFolder, "a.md"), "NFC", "utf8");
+        await fs.writeFile(path.join(directory, nfdFolder, "b.md"), "NFD", "utf8");
+        const adapter = createNormalisingAdapter(directory);
+
+        await expect(adapter.getFiles()).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.scanDirectory()).rejects.toThrow(/ambiguous/i);
+
+        await expect(fs.readFile(path.join(directory, nfcFolder, "a.md"), "utf8")).resolves.toBe("NFC");
+        await expect(fs.readFile(path.join(directory, nfdFolder, "b.md"), "utf8")).resolves.toBe("NFD");
+    });
+
+    it("rechecks the directory after a unique file is cached", async () => {
+        const directory = await createVault();
+        const nfcName = "café.md";
+        const nfdName = nfcName.normalize("NFD");
+        await fs.writeFile(path.join(directory, nfdName), "NFD", "utf8");
+        const adapter = createNormalisingAdapter(directory);
+
+        await expect(adapter.getAbstractFileByPath(nfcName)).resolves.toMatchObject({ path: nfdName });
+        await fs.writeFile(path.join(directory, nfcName), "NFC", "utf8");
+
+        await expect(adapter.getAbstractFileByPath(nfcName)).rejects.toThrow(/ambiguous/i);
+        await expect(fs.readFile(path.join(directory, nfcName), "utf8")).resolves.toBe("NFC");
+        await expect(fs.readFile(path.join(directory, nfdName), "utf8")).resolves.toBe("NFD");
+    });
+
+    it.each([
+        ["Foo", "foo"],
+        ["Café", "café".normalize("NFD")],
+    ])("rejects case-insensitive parent aliases %s and %s containing different files", async (first, second) => {
+        const directory = await createVault();
+        for (const [parent, name] of [
+            [first, "one.md"],
+            [second, "two.md"],
+        ]) {
+            await fs.mkdir(path.join(directory, parent));
+            await fs.writeFile(path.join(directory, parent, name), name);
+        }
+        const adapter = createNormalisingAdapter(directory, true);
+
+        await expect(adapter.getFiles()).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.scanDirectory()).rejects.toThrow(/ambiguous/i);
+        await expect(fs.readFile(path.join(directory, first, "one.md"), "utf8")).resolves.toBe("one.md");
+        await expect(fs.readFile(path.join(directory, second, "two.md"), "utf8")).resolves.toBe("two.md");
+    });
+
+    it.each([
+        { version: 0, caseInsensitive: true },
+        { version: 1, caseInsensitive: false },
+    ])(
+        "compatibility: retains distinct case paths in mode $version with case-insensitive matching $caseInsensitive",
+        async ({ version, caseInsensitive }) => {
+            const directory = await createVault();
+            const names = ["Café/one.md", "café/two.md".normalize("NFD")];
+            for (const name of names) {
+                await fs.mkdir(path.dirname(path.join(directory, name)));
+                await fs.writeFile(path.join(directory, name), name);
+            }
+            const adapter = new NodeFileSystemAdapter(
+                directory,
+                undefined,
+                () => version,
+                () => caseInsensitive
+            );
+
+            expect((await adapter.getFiles()).map((file) => file.path).sort()).toEqual([...names].sort());
+            for (const name of names) await expect(adapter.storage.read(name)).resolves.toBe(name);
+        }
+    );
+
+    it("refuses reconstruction before starting remote activity when parent aliases are ambiguous", async () => {
+        const directory = await createVault();
+        for (const name of ["Café/one.md", "café/two.md".normalize("NFD")]) {
+            await fs.mkdir(path.dirname(path.join(directory, name)));
+            await fs.writeFile(path.join(directory, name), name);
+        }
+        const adapter = createNormalisingAdapter(directory, true);
+        const settings = {
+            ...DEFAULT_SETTINGS,
+            pathNormalizationVersion: 1 as const,
+            handleFilenameCaseSensitive: false,
+        };
+        const setting = { currentSettings: () => settings, suspendAllSync: { addHandler: vi.fn() } };
+        const runBoundedRemoteActivity = vi.fn(async () => undefined);
+        const rebuilder = new ServiceRebuilder({
+            setting,
+            storageAccess: { getFileNames: async () => (await adapter.getFiles()).map((file) => file.path) },
+            database: {
+                onDatabaseReset: { addHandler: vi.fn() },
+                isDatabaseReady: () => true,
+                localDatabase: { findAllDocs: async function* () {} },
+            },
+            vault: { isTargetFile: async () => true },
+            path: new PathServiceCompat(new ServiceContext(), { settingService: setting as never }),
+            replicator: { runBoundedRemoteActivity },
+            UI: { showMarkdownDialog: vi.fn(async () => undefined) },
+        } as unknown as ServiceRebuilderDependencies);
+
+        await expect(rebuilder.$rebuildEverything()).rejects.toThrow(/ambiguous/i);
+        expect(runBoundedRemoteActivity).not.toHaveBeenCalled();
+    });
+
+    it("uses fresh listings after external additions, renames, deletions, and collisions", async () => {
+        const directory = await createVault();
+        const nfdName = "café.md".normalize("NFD");
+        await fs.writeFile(path.join(directory, nfdName), "original");
+        const adapter = createNormalisingAdapter(directory);
+        expect((await adapter.getFiles()).map((file) => file.path)).toEqual([nfdName]);
+
+        const renamed = "résumé.md".normalize("NFD");
+        await fs.rename(path.join(directory, nfdName), path.join(directory, renamed));
+        await fs.writeFile(path.join(directory, "new.md"), "new");
+        expect((await adapter.getFiles()).map((file) => file.path).sort()).toEqual(["new.md", renamed]);
+
+        await fs.rm(path.join(directory, "new.md"));
+        expect((await adapter.getFiles()).map((file) => file.path)).toEqual([renamed]);
+        await fs.writeFile(path.join(directory, renamed.normalize("NFC")), "collision");
+        await expect(adapter.getFiles()).rejects.toThrow(/ambiguous/i);
+    });
+
+    it("retains the storage boundary for exact metadata reads and directory scans", async () => {
+        const directory = await createVault();
+        const outside = await createVault();
+        await fs.writeFile(path.join(outside, "note.md"), "outside");
+        await fs.symlink(outside, path.join(directory, "linked"), "dir");
+        const adapter = createNormalisingAdapter(directory);
+
+        await expect(adapter.getFiles()).resolves.toEqual([]);
+        await expect(adapter.storage.statExact("linked/note.md")).rejects.toThrow(/symbolic links/i);
+        await expect(adapter.storage.write("linked/note.md", "changed")).rejects.toThrow(/symbolic links/i);
+        await expect(fs.readFile(path.join(outside, "note.md"), "utf8")).resolves.toBe("outside");
+    });
+
+    it("detects NFC and case collisions when lookup is case-insensitive", async () => {
+        const directory = await createVault();
+        const upperName = "Café.md";
+        const lowerNfdName = "café.md".normalize("NFD");
+        await fs.writeFile(path.join(directory, upperName), "upper", "utf8");
+        await fs.writeFile(path.join(directory, lowerNfdName), "lower", "utf8");
+        const adapter = createNormalisingAdapter(directory, true);
+
+        await expect(adapter.getAbstractFileByPathInsensitive("CAFÉ.md")).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.getFiles()).rejects.toThrow(/ambiguous/i);
+        await expect(adapter.scanDirectory()).rejects.toThrow(/ambiguous/i);
+        await expect(fs.readFile(path.join(directory, upperName), "utf8")).resolves.toBe("upper");
+        await expect(fs.readFile(path.join(directory, lowerNfdName), "utf8")).resolves.toBe("lower");
+    });
+
+    it("retains exact-path behaviour when path normalisation is disabled", async () => {
+        const directory = await createVault();
+        const nfcName = "café.md";
+        const nfdName = nfcName.normalize("NFD");
+        await fs.writeFile(path.join(directory, nfdName), "NFD", "utf8");
+        const adapter = new NodeFileSystemAdapter(directory);
+
+        await expect(adapter.getAbstractFileByPath(nfcName)).resolves.toBeNull();
+        await adapter.storage.write(nfcName, "NFC");
+
+        await expect(fs.readFile(path.join(directory, nfcName), "utf8")).resolves.toBe("NFC");
+        await expect(fs.readFile(path.join(directory, nfdName), "utf8")).resolves.toBe("NFD");
+    });
+});

src/apps/cli/adapters/NodeVaultAdapter.ts

@@ -2,6 +2,7 @@ import type { FilePath, UXDataWriteOptions } from "@vrtmrz/livesync-commonlib/co
 import type { IVaultAdapter } from "@vrtmrz/livesync-commonlib/compat/serviceModules/adapters";
 import type { NodeFile, NodeFolder } from "./NodeTypes";
 import { NodeStorageAdapter } from "@vrtmrz/livesync-commonlib/node";
+import { UnicodeResolvingNodeStorageAdapter } from "./UnicodeResolvingNodeStorageAdapter";
 
 /**
  * Vault adapter implementation for Node.js
@@ -73,8 +74,16 @@ export class NodeVaultAdapter implements IVaultAdapter<NodeFile> {
     }
 
     private async toNodeFile(path: string): Promise<NodeFile> {
-        const stat = await this.storage.stat(path);
+        const resolvedPath =
+            this.storage instanceof UnicodeResolvingNodeStorageAdapter
+                ? await this.storage.resolveLogicalPath(path, undefined, false)
+                : path;
+        if (resolvedPath === null) throw new Error(`Could not read created file metadata: ${path}`);
+        const stat =
+            this.storage instanceof UnicodeResolvingNodeStorageAdapter
+                ? await this.storage.statExact(resolvedPath)
+                : await this.storage.stat(resolvedPath);
         if (stat?.type !== "file") throw new Error(`Could not read created file metadata: ${path}`);
-        return { path: path as FilePath, stat };
+        return { path: resolvedPath as FilePath, stat };
     }
 }

src/apps/cli/adapters/UnicodeResolvingNodeStorageAdapter.ts

@@ -0,0 +1,205 @@
+import { NodeStorageAdapter, validateStoragePath } from "@vrtmrz/livesync-commonlib/node";
+
+export class AmbiguousNormalisedPathError extends Error {
+    constructor(path: string) {
+        super(`Ambiguous path after Unicode normalisation: ${path}`);
+        this.name = "AmbiguousNormalisedPathError";
+    }
+}
+
+/** Resolves NFC-equivalent logical paths against current Node storage listings. */
+export class UnicodeResolvingNodeStorageAdapter extends NodeStorageAdapter {
+    constructor(
+        rootPath: string,
+        private readonly getPathNormalizationVersion: () => number = () => 0,
+        private readonly isCaseInsensitive: () => boolean = () => false
+    ) {
+        super(rootPath);
+    }
+
+    get isUnicodePathNormalizationEnabled(): boolean {
+        return this.getPathNormalizationVersion() === 1;
+    }
+
+    /** Read metadata for an entry already resolved or obtained from a storage listing. */
+    async statExact(path: string) {
+        return await super.trystat(path);
+    }
+
+    /** Inspect a physical directory once before descending into its enumerated entries. */
+    async listExact(path: string) {
+        const entries = await super.list(path);
+        if (this.isUnicodePathNormalizationEnabled) {
+            const caseInsensitive = this.isCaseInsensitive();
+            const names = new Map<string, string>();
+            for (const entry of [...entries.files, ...entries.folders]) {
+                const key = this.comparisonKey(entry, caseInsensitive);
+                if (names.has(key)) throw new AmbiguousNormalisedPathError(entry);
+                names.set(key, entry);
+            }
+        }
+        return entries;
+    }
+
+    async resolveLogicalPath(
+        path: string,
+        caseInsensitive = this.isCaseInsensitive(),
+        allowMissing = true
+    ): Promise<string | null> {
+        if (!this.isUnicodePathNormalizationEnabled) return path;
+
+        validateStoragePath(path, true);
+        if (path === "") return "";
+
+        const segments = path.split("/");
+        let resolvedParent = "";
+
+        for (let index = 0; index < segments.length; index++) {
+            const segment = segments[index];
+            const entries = await super.list(resolvedParent);
+            const candidates = [...entries.files, ...entries.folders];
+            const requestedKey = this.comparisonKey(segment, caseInsensitive);
+            const matches = candidates.filter((entryPath) => {
+                const entryName = entryPath.slice(resolvedParent === "" ? 0 : resolvedParent.length + 1);
+                return this.comparisonKey(entryName, caseInsensitive) === requestedKey;
+            });
+
+            if (matches.length > 1) throw new AmbiguousNormalisedPathError(path);
+            if (matches.length === 1) {
+                resolvedParent = matches[0];
+                continue;
+            }
+
+            if (!allowMissing) return null;
+            const remainingPath = segments.slice(index).join("/");
+            return resolvedParent === "" ? remainingPath : `${resolvedParent}/${remainingPath}`;
+        }
+
+        return resolvedParent;
+    }
+
+    override async exists(path: string, caseInsensitive = this.isCaseInsensitive()): Promise<boolean> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, false);
+        if (resolvedPath === null) return false;
+        return await super.exists(resolvedPath);
+    }
+
+    override async trystat(path: string, caseInsensitive = this.isCaseInsensitive()) {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, false);
+        if (resolvedPath === null) return null;
+        return await super.trystat(resolvedPath);
+    }
+
+    override async stat(path: string, caseInsensitive = this.isCaseInsensitive()) {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, false);
+        if (resolvedPath === null) return null;
+        return await super.trystat(resolvedPath);
+    }
+
+    override async mkdir(path: string, caseInsensitive = this.isCaseInsensitive()): Promise<void> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, true);
+        if (resolvedPath === null) throw new Error(`Could not resolve path: ${path}`);
+        await super.mkdir(resolvedPath);
+    }
+
+    override async remove(path: string, caseInsensitive = this.isCaseInsensitive()): Promise<void> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, false);
+        await super.remove(resolvedPath ?? path);
+    }
+
+    override async read(path: string, caseInsensitive = this.isCaseInsensitive()): Promise<string> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, false);
+        return await super.read(resolvedPath ?? path);
+    }
+
+    override async readBinary(path: string, caseInsensitive = this.isCaseInsensitive()): Promise<ArrayBuffer> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, false);
+        return await super.readBinary(resolvedPath ?? path);
+    }
+
+    override async write(
+        path: string,
+        data: string,
+        options?: Parameters<NodeStorageAdapter["write"]>[2],
+        caseInsensitive = this.isCaseInsensitive()
+    ): Promise<void> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, true);
+        if (resolvedPath === null) throw new Error(`Could not resolve path: ${path}`);
+        await super.write(resolvedPath, data, options);
+    }
+
+    override async writeBinary(
+        path: string,
+        data: ArrayBuffer,
+        options?: Parameters<NodeStorageAdapter["writeBinary"]>[2],
+        caseInsensitive = this.isCaseInsensitive()
+    ): Promise<void> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, true);
+        if (resolvedPath === null) throw new Error(`Could not resolve path: ${path}`);
+        await super.writeBinary(resolvedPath, data, options);
+    }
+
+    override async append(
+        path: string,
+        data: string,
+        options?: Parameters<NodeStorageAdapter["append"]>[2],
+        caseInsensitive = this.isCaseInsensitive()
+    ): Promise<void> {
+        const resolvedPath = await this.resolveLogicalPath(path, caseInsensitive, true);
+        if (resolvedPath === null) throw new Error(`Could not resolve path: ${path}`);
+        await super.append(resolvedPath, data, options);
+    }
+
+    override async rename(
+        sourcePath: string,
+        targetPath: string,
+        caseInsensitive = this.isCaseInsensitive()
+    ): Promise<void> {
+        const resolvedSource = await this.resolveLogicalPath(sourcePath, caseInsensitive, false);
+        if (resolvedSource === null) return await super.rename(sourcePath, targetPath);
+
+        const resolvedTarget = await this.resolveLogicalPath(targetPath, caseInsensitive, true);
+        if (resolvedTarget === null) throw new Error(`Could not resolve path: ${targetPath}`);
+
+        // Preserve explicit case-only or Unicode-spelling renames when the target resolves to the source.
+        const sourceKey = this.comparisonKey(resolvedSource, caseInsensitive);
+        const targetKey = this.comparisonKey(resolvedTarget, caseInsensitive);
+        const target =
+            sourceKey === targetKey && resolvedTarget === resolvedSource && targetPath !== resolvedSource
+                ? await this.resolveRenameTargetSpelling(targetPath, caseInsensitive)
+                : resolvedTarget;
+
+        await super.rename(resolvedSource, target);
+    }
+
+    override async list(basePath: string, caseInsensitive = this.isCaseInsensitive()) {
+        const resolvedPath = await this.resolveLogicalPath(basePath, caseInsensitive, false);
+        if (resolvedPath === null) return { files: [], folders: [] };
+        return await super.list(resolvedPath);
+    }
+
+    private async resolveRenameTargetSpelling(path: string, caseInsensitive: boolean): Promise<string> {
+        validateStoragePath(path, false);
+        const segments = path.split("/");
+        const leaf = segments.pop();
+        if (leaf === undefined) throw new Error(`Could not resolve path: ${path}`);
+        const parentPath = segments.join("/");
+        const resolvedParent = await this.resolveLogicalPath(parentPath, caseInsensitive, true);
+        if (resolvedParent === null) throw new Error(`Could not resolve path: ${path}`);
+
+        const entries = await super.list(resolvedParent);
+        const requestedKey = this.comparisonKey(leaf, caseInsensitive);
+        const matches = [...entries.files, ...entries.folders].filter((entryPath) => {
+            const entryName = entryPath.slice(resolvedParent === "" ? 0 : resolvedParent.length + 1);
+            return this.comparisonKey(entryName, caseInsensitive) === requestedKey;
+        });
+        if (matches.length > 1) throw new AmbiguousNormalisedPathError(path);
+
+        return resolvedParent === "" ? leaf : `${resolvedParent}/${leaf}`;
+    }
+
+    private comparisonKey(segment: string, caseInsensitive: boolean): string {
+        const normalisedSegment = segment.normalize("NFC");
+        return caseInsensitive ? normalisedSegment.toLowerCase() : normalisedSegment;
+    }
+}