Skip to content

Use Effect FileSystem for workspace reads #3675

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
cursor wants to merge 4 commits into
base: main
Choose a base branch
from
+107 −97
Draft

Use Effect FileSystem for workspace reads #3675

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
ddf731d
Use Effect FileSystem for workspace reads
cursoragent Jul 3, 2026
ccfad54
Test workspace reads use injected filesystem
cursoragent Jul 3, 2026
b356b22
Provide path service in workspace filesystem test
cursoragent Jul 3, 2026
e72791d
Format workspace filesystem effect chains
cursoragent Jul 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
55 changes: 52 additions & 3 deletions apps/server/src/workspace/WorkspaceFileSystem.test.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,9 +1,10 @@
import * as NodeServices from "@effect/platform-node/NodeServices";
import { it, describe, expect } from "@effect/vitest";
import { assert, it, describe, expect } from "@effect/vitest";
import * as Effect from "effect/Effect";
import * as FileSystem from "effect/FileSystem";
import * as Layer from "effect/Layer";
import * as Path from "effect/Path";
import * as PlatformError from "effect/PlatformError";

import * as ServerConfig from "../config.ts";
import * as VcsDriverRegistry from "../vcs/VcsDriverRegistry.ts";
Expand All @@ -30,6 +31,34 @@ const TestLayer = Layer.empty.pipe(
Layer.provideMerge(NodeServices.layer),
);

const OpenFailureFileSystemLayer = Layer.effect(
FileSystem.FileSystem,
Effect.gen(function* () {
const fileSystem = yield* FileSystem.FileSystem;

return {
...fileSystem,
open: (path, options) =>
Effect.fail(
PlatformError.systemError({
_tag: "PermissionDenied",
module: "FileSystem",
method: "open",
pathOrDescriptor: String(path),
description: `open intercepted by FileSystem test layer (options: ${String(Boolean(options))})`,
}),
),
} satisfies FileSystem.FileSystem;
}),
).pipe(Layer.provide(NodeServices.layer));

const WorkspaceFileSystemOpenFailureLayer = WorkspaceFileSystem.layer.pipe(
Layer.provide(WorkspacePaths.layer),
Layer.provide(Layer.mock(WorkspaceEntries.WorkspaceEntries)({})),
Layer.provideMerge(OpenFailureFileSystemLayer),
Layer.provideMerge(Path.layer),
);

const makeTempDir = Effect.gen(function* () {
const fileSystem = yield* FileSystem.FileSystem;
return yield* fileSystem.makeTempDirectoryScoped({
Expand All @@ -51,6 +80,26 @@ const writeTextFile = Effect.fn("writeTextFile")(function* (
yield* fileSystem.writeFileString(absolutePath, contents).pipe(Effect.orDie);
});

it.effect("WorkspaceFileSystem.readFile opens files through the injected FileSystem service", () =>
Effect.gen(function* () {
const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
const cwd = yield* makeTempDir;
yield* writeTextFile(cwd, "src/index.ts", "export const answer = 42;\n");
const fileSystem = yield* FileSystem.FileSystem;
const resolvedPath = yield* fileSystem.realPath(`${cwd}/src/index.ts`);

const error = yield* workspaceFileSystem
.readFile({ cwd, relativePath: "src/index.ts" })
.pipe(Effect.flip);

assert.instanceOf(error, WorkspaceFileSystem.WorkspaceFileSystemOperationError);
assert.equal(error.operation, "open");
assert.equal(error.operationPath, resolvedPath);
assert.instanceOf(error.cause, PlatformError.PlatformError);
assert.equal((error.cause as PlatformError.PlatformError).reason._tag, "PermissionDenied");
}).pipe(Effect.provide(WorkspaceFileSystemOpenFailureLayer)),
);

it.layer(TestLayer, { excludeTestServices: true })("WorkspaceFileSystemLive", (it) => {
describe("readFile", () => {
it.effect("reads UTF-8 files relative to the workspace root", () =>
Expand Down Expand Up @@ -185,8 +234,8 @@ it.layer(TestLayer, { excludeTestServices: true })("WorkspaceFileSystemLive", (i
operationPath: resolvedPath,
operation: "realpath-target",
});
expect(error.cause).toBeInstanceOf(Error);
expect((error.cause as NodeJS.ErrnoException).code).toBe("ENOENT");
expect(error.cause).toBeInstanceOf(PlatformError.PlatformError);
expect((error.cause as PlatformError.PlatformError).reason._tag).toBe("NotFound");
}),
);
});
Expand Down
149 changes: 55 additions & 94 deletions apps/server/src/workspace/WorkspaceFileSystem.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,3 @@
// @effect-diagnostics nodeBuiltinImport:off
/**
* WorkspaceFileSystem - Effect service contract for workspace file mutations.
*
Expand All @@ -7,8 +6,6 @@
*
* @module WorkspaceFileSystem
*/
import * as NodeFSP from "node:fs/promises";

import type {
ProjectReadFileInput,
ProjectReadFileResult,
Expand All @@ -19,6 +16,7 @@ import * as Context from "effect/Context";
import * as Effect from "effect/Effect";
import * as FileSystem from "effect/FileSystem";
import * as Layer from "effect/Layer";
import * as Option from "effect/Option";
import * as Path from "effect/Path";
import * as Schema from "effect/Schema";

Expand Down Expand Up @@ -140,30 +138,28 @@ export const make = Effect.gen(function* () {
relativePath: input.relativePath,
});

const realWorkspaceRoot = yield* Effect.tryPromise({
try: () => NodeFSP.realpath(input.cwd),
catch: (cause) =>
new WorkspaceFileSystemOperationError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: target.absolutePath,
operationPath: input.cwd,
operation: "realpath-workspace-root",
cause,
}),
});
const realTargetPath = yield* Effect.tryPromise({
try: () => NodeFSP.realpath(target.absolutePath),
catch: (cause) =>
const toOperationError =
(
operation: WorkspaceFileSystemOperationError["operation"],
operationPath: string,
resolvedPath = target.absolutePath,
) =>
(cause: unknown) =>
new WorkspaceFileSystemOperationError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: target.absolutePath,
operationPath: target.absolutePath,
operation: "realpath-target",
resolvedPath,
operationPath,
operation,
cause,
}),
});
});

const realWorkspaceRoot = yield* fileSystem
.realPath(input.cwd)
.pipe(Effect.mapError(toOperationError("realpath-workspace-root", input.cwd)));
const realTargetPath = yield* fileSystem
.realPath(target.absolutePath)
.pipe(Effect.mapError(toOperationError("realpath-target", target.absolutePath)));
const relativeRealPath = path.relative(realWorkspaceRoot, realTargetPath);
if (
relativeRealPath.startsWith(`..${path.sep}`) ||
Expand All @@ -178,84 +174,49 @@ export const make = Effect.gen(function* () {
});
}

return yield* Effect.acquireUseRelease(
Effect.tryPromise({
try: () => NodeFSP.open(realTargetPath, "r"),
catch: (cause) =>
new WorkspaceFileSystemOperationError({
return yield* Effect.scoped(

@macroscopeapp macroscopeapp Bot Jul 3, 2026

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

🟡 Medium workspace/WorkspaceFileSystem.ts:177

readFile no longer wraps file-handle close failures in WorkspaceFileSystemOperationError. fileSystem.open() is a scoped resource, and Effect.scoped propagates scope-finalizer errors on exit, so a close error escapes as a raw PlatformError after the body succeeds. This breaks the advertised WorkspaceFileSystemError contract — downstream error handling in ws.ts will hit unexpectedCompatibilityError(error) and throw instead of returning a ProjectReadFileError response. Consider catching close errors from the scope finalizer and mapping them to WorkspaceFileSystemOperationError with operation "close", as the previous acquireUseRelease implementation did.

🚀 Reply "fix it for me" or copy this AI Prompt for your agent: 
In file @apps/server/src/workspace/WorkspaceFileSystem.ts around line 177:

`readFile` no longer wraps file-handle close failures in `WorkspaceFileSystemOperationError`. `fileSystem.open()` is a scoped resource, and `Effect.scoped` propagates scope-finalizer errors on exit, so a close error escapes as a raw `PlatformError` after the body succeeds. This breaks the advertised `WorkspaceFileSystemError` contract — downstream error handling in `ws.ts` will hit `unexpectedCompatibilityError(error)` and throw instead of returning a `ProjectReadFileError` response. Consider catching close errors from the scope finalizer and mapping them to `WorkspaceFileSystemOperationError` with operation `"close"`, as the previous `acquireUseRelease` implementation did.

Effect.gen(function* () {
const file = yield* fileSystem
.open(realTargetPath, { flag: "r" })
.pipe(Effect.mapError(toOperationError("open", realTargetPath, realTargetPath)));
const stat = yield* file.stat.pipe(
Effect.mapError(toOperationError("stat", realTargetPath, realTargetPath)),
);
if (stat.type !== "File") {
return yield* new WorkspacePathNotFileError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
operationPath: realTargetPath,
operation: "open",
cause,
}),
}),
(handle) =>
Effect.gen(function* () {
const stat = yield* Effect.tryPromise({
try: () => handle.stat(),
catch: (cause) =>
new WorkspaceFileSystemOperationError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
operationPath: realTargetPath,
operation: "stat",
cause,
}),
});
if (!stat.isFile()) {
return yield* new WorkspacePathNotFileError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
});
}
}

const bytesToRead = Math.min(stat.size, PROJECT_READ_FILE_MAX_BYTES);
const buffer = Buffer.alloc(bytesToRead);
const { bytesRead } = yield* Effect.tryPromise({
try: () => handle.read(buffer, 0, bytesToRead, 0),
catch: (cause) =>
new WorkspaceFileSystemOperationError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
operationPath: realTargetPath,
operation: "read",
cause,
}),
const byteLength = Number(stat.size);
const truncated = stat.size > BigInt(PROJECT_READ_FILE_MAX_BYTES);
const bytesToRead = truncated ? PROJECT_READ_FILE_MAX_BYTES : byteLength;
const fileBytes =
bytesToRead === 0
? new Uint8Array()
: Option.getOrElse(
yield* file
.readAlloc(bytesToRead)
.pipe(Effect.mapError(toOperationError("read", realTargetPath, realTargetPath))),
() => new Uint8Array(),
);
if (fileBytes.includes(0)) {
return yield* new WorkspaceBinaryFileError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
});
const fileBytes = buffer.subarray(0, bytesRead);
if (fileBytes.includes(0)) {
return yield* new WorkspaceBinaryFileError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
});
}
}

return {
relativePath: target.relativePath,
contents: new TextDecoder("utf-8").decode(fileBytes),
byteLength: stat.size,
truncated: stat.size > PROJECT_READ_FILE_MAX_BYTES,
};
}),
(handle) =>
Effect.tryPromise({
try: () => handle.close(),
catch: (cause) =>
new WorkspaceFileSystemOperationError({
workspaceRoot: input.cwd,
relativePath: input.relativePath,
resolvedPath: realTargetPath,
operationPath: realTargetPath,
operation: "close",
cause,
}),
}),
return {
relativePath: target.relativePath,
contents: new TextDecoder("utf-8").decode(fileBytes),
byteLength,
truncated,
};
}),
);
});

Expand Down
Loading