feat: Add centralized filesystem module for Bun.file migration (#14117)

packages/opencode/src/util/filesystem.ts

@@ -1,18 +1,76 @@
+import { mkdir, readFile, writeFile } from "fs/promises"
+import { existsSync, statSync } from "fs"
+import { lookup } from "mime-types"
 import { realpathSync } from "fs"
 import { dirname, join, relative } from "path"
 
 export namespace Filesystem {
-  export const exists = (p: string) =>
-    Bun.file(p)
-      .stat()
-      .then(() => true)
-      .catch(() => false)
+  // Fast sync version for metadata checks
+  export async function exists(p: string): Promise<boolean> {
+    return existsSync(p)
+  }
+
+  export async function isDir(p: string): Promise<boolean> {
+    try {
+      return statSync(p).isDirectory()
+    } catch {
+      return false
+    }
+  }
+
+  export async function size(p: string): Promise<number> {
+    try {
+      return statSync(p).size
+    } catch {
+      return 0
+    }
+  }
+
+  export async function readText(p: string): Promise<string> {
+    return readFile(p, "utf-8")
+  }
+
+  export async function readJson<T>(p: string): Promise<T> {
+    return JSON.parse(await readFile(p, "utf-8"))
+  }
+
+  export async function readBytes(p: string): Promise<Buffer> {
+    return readFile(p)
+  }
+
+  function isEnoent(e: unknown): e is { code: "ENOENT" } {
+    return typeof e === "object" && e !== null && "code" in e && (e as { code: string }).code === "ENOENT"
+  }
+
+  export async function write(p: string, content: string | Buffer, mode?: number): Promise<void> {
+    try {
+      if (mode) {
+        await writeFile(p, content, { mode })
+      } else {
+        await writeFile(p, content)
+      }
+    } catch (e) {
+      if (isEnoent(e)) {
+        await mkdir(dirname(p), { recursive: true })
+        if (mode) {
+          await writeFile(p, content, { mode })
+        } else {
+          await writeFile(p, content)
+        }
+        return
+      }
+      throw e
+    }
+  }
+
+  export async function writeJson(p: string, data: unknown, mode?: number): Promise<void> {
+    return write(p, JSON.stringify(data, null, 2), mode)
+  }
+
+  export function mimeType(p: string): string {
+    return lookup(p) || "application/octet-stream"
+  }
 
-  export const isDir = (p: string) =>
-    Bun.file(p)
-      .stat()
-      .then((s) => s.isDirectory())
-      .catch(() => false)
   /**
    * On Windows, normalize a path to its canonical casing using the filesystem.
    * This is needed because Windows paths are case-insensitive but LSP servers
@@ -26,6 +84,7 @@ export namespace Filesystem {
       return p
     }
   }
+
   export function overlaps(a: string, b: string) {
     const relA = relative(a, b)
     const relB = relative(b, a)