core: use Filesystem utility for consistent file operations with better error handling

packages/opencode/src/session/prompt.ts

@@ -27,6 +27,7 @@ import { MCP } from "../mcp"
 import { LSP } from "../lsp"
 import { ReadTool } from "../tool/read"
 import { FileTime } from "../file/time"
+import { Filesystem } from "../util/filesystem"
 import { Flag } from "../flag/flag"
 import { ulid } from "ulid"
 import { spawn } from "child_process"
@@ -1082,11 +1083,9 @@ export namespace SessionPrompt {
               // have to normalize, symbol search returns absolute paths
               // Decode the pathname since URL constructor doesn't automatically decode it
               const filepath = fileURLToPath(part.url)
-              const stat = await Bun.file(filepath)
-                .stat()
-                .catch(() => undefined)
+              const s = Filesystem.stat(filepath)
 
-              if (stat?.isDirectory()) {
+              if (s?.isDirectory()) {
                 part.mime = "application/x-directory"
               }
 
@@ -1233,14 +1232,13 @@ export namespace SessionPrompt {
                 ]
               }
 
-              const file = Bun.file(filepath)
               FileTime.read(input.sessionID, filepath)
               return [
                 {
                   messageID: info.id,
                   sessionID: input.sessionID,
                   type: "text",
-                  text: `Called the Read tool with the following input: {\"filePath\":\"${filepath}\"}`,
+                  text: `Called the Read tool with the following input: {"filePath":"${filepath}"}`,
                   synthetic: true,
                 },
                 {
@@ -1248,7 +1246,8 @@ export namespace SessionPrompt {
                   messageID: info.id,
                   sessionID: input.sessionID,
                   type: "file",
-                  url: `data:${part.mime};base64,` + Buffer.from(await file.bytes()).toString("base64"),
+                  url:
+                    `data:${part.mime};base64,` + Buffer.from(await Filesystem.readBytes(filepath)).toString("base64"),
                   mime: part.mime,
                   filename: part.filename!,
                   source: part.source,
@@ -1354,7 +1353,7 @@ export namespace SessionPrompt {
     // Switching from plan mode to build mode
     if (input.agent.name !== "plan" && assistantMessage?.info.agent === "plan") {
       const plan = Session.plan(input.session)
-      const exists = await Bun.file(plan).exists()
+      const exists = await Filesystem.exists(plan)
       if (exists) {
         const part = await Session.updatePart({
           id: Identifier.ascending("part"),
@@ -1373,7 +1372,7 @@ export namespace SessionPrompt {
     // Entering plan mode
     if (input.agent.name === "plan" && assistantMessage?.info.agent !== "plan") {
       const plan = Session.plan(input.session)
-      const exists = await Bun.file(plan).exists()
+      const exists = await Filesystem.exists(plan)
       if (!exists) await fs.mkdir(path.dirname(plan), { recursive: true })
       const part = await Session.updatePart({
         id: Identifier.ascending("part"),