fix: properly encode file URLs with special characters (#12424)

packages/opencode/test/session/prompt-special-chars.test.ts

@@ -0,0 +1,56 @@
+import path from "path"
+import { describe, expect, test } from "bun:test"
+import { fileURLToPath } from "url"
+import { Instance } from "../../src/project/instance"
+import { Log } from "../../src/util/log"
+import { Session } from "../../src/session"
+import { SessionPrompt } from "../../src/session/prompt"
+import { MessageV2 } from "../../src/session/message-v2"
+import { tmpdir } from "../fixture/fixture"
+
+Log.init({ print: false })
+
+describe("session.prompt special characters", () => {
+  test("handles filenames with # character", async () => {
+    await using tmp = await tmpdir({
+      git: true,
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "file#name.txt"), "special content\n")
+      },
+    })
+
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const template = "Read @file#name.txt"
+        const parts = await SessionPrompt.resolvePromptParts(template)
+        const fileParts = parts.filter((part) => part.type === "file")
+
+        expect(fileParts.length).toBe(1)
+        expect(fileParts[0].filename).toBe("file#name.txt")
+
+        // Verify the URL is properly encoded (# should be %23)
+        expect(fileParts[0].url).toContain("%23")
+
+        // Verify the URL can be correctly converted back to a file path
+        const decodedPath = fileURLToPath(fileParts[0].url)
+        expect(decodedPath).toBe(path.join(tmp.path, "file#name.txt"))
+
+        const message = await SessionPrompt.prompt({
+          sessionID: session.id,
+          parts,
+          noReply: true,
+        })
+        const stored = await MessageV2.get({ sessionID: session.id, messageID: message.info.id })
+
+        // Verify the file content was read correctly
+        const textParts = stored.parts.filter((part) => part.type === "text")
+        const hasContent = textParts.some((part) => part.text.includes("special content"))
+        expect(hasContent).toBe(true)
+
+        await Session.remove(session.id)
+      },
+    })
+  })
+})