tweak: add new ContextOverflowError type (#12777)

packages/opencode/test/session/message-v2.test.ts

@@ -1,4 +1,5 @@
 import { describe, expect, test } from "bun:test"
+import { APICallError } from "ai"
 import { MessageV2 } from "../../src/session/message-v2"
 import type { Provider } from "../../src/provider/provider"
 
@@ -786,12 +787,26 @@ describe("session.message-v2.toModelMessage", () => {
 })
 
 describe("session.message-v2.fromError", () => {
+  test("serializes context_length_exceeded as ContextOverflowError", () => {
+    const input = {
+      type: "error",
+      error: {
+        code: "context_length_exceeded",
+      },
+    }
+    const result = MessageV2.fromError(input, { providerID: "test" })
+
+    expect(result).toStrictEqual({
+      name: "ContextOverflowError",
+      data: {
+        message: "Input exceeds context window of this model",
+        responseBody: JSON.stringify(input),
+      },
+    })
+  })
+
   test("serializes response error codes", () => {
     const cases = [
-      {
-        code: "context_length_exceeded",
-        message: "Input exceeds context window of this model",
-      },
       {
         code: "insufficient_quota",
         message: "Quota exceeded. Check your plan and billing details.",
@@ -827,6 +842,75 @@ describe("session.message-v2.fromError", () => {
     })
   })
 
+  test("maps github-copilot 403 to reauth guidance", () => {
+    const error = new APICallError({
+      message: "forbidden",
+      url: "https://api.githubcopilot.com/v1/chat/completions",
+      requestBodyValues: {},
+      statusCode: 403,
+      responseHeaders: { "content-type": "application/json" },
+      responseBody: '{"error":"forbidden"}',
+      isRetryable: false,
+    })
+
+    const result = MessageV2.fromError(error, { providerID: "github-copilot" })
+
+    expect(result).toStrictEqual({
+      name: "APIError",
+      data: {
+        message:
+          "Please reauthenticate with the copilot provider to ensure your credentials work properly with OpenCode.",
+        statusCode: 403,
+        isRetryable: false,
+        responseHeaders: { "content-type": "application/json" },
+        responseBody: '{"error":"forbidden"}',
+        metadata: {
+          url: "https://api.githubcopilot.com/v1/chat/completions",
+        },
+      },
+    })
+  })
+
+  test("detects context overflow from APICallError provider messages", () => {
+    const cases = [
+      "prompt is too long: 213462 tokens > 200000 maximum",
+      "Your input exceeds the context window of this model",
+      "The input token count (1196265) exceeds the maximum number of tokens allowed (1048575)",
+      "Please reduce the length of the messages or completion",
+      "400 status code (no body)",
+      "413 status code (no body)",
+    ]
+
+    cases.forEach((message) => {
+      const error = new APICallError({
+        message,
+        url: "https://example.com",
+        requestBodyValues: {},
+        statusCode: 400,
+        responseHeaders: { "content-type": "application/json" },
+        isRetryable: false,
+      })
+      const result = MessageV2.fromError(error, { providerID: "test" })
+      expect(MessageV2.ContextOverflowError.isInstance(result)).toBe(true)
+    })
+  })
+
+  test("does not classify 429 no body as context overflow", () => {
+    const result = MessageV2.fromError(
+      new APICallError({
+        message: "429 status code (no body)",
+        url: "https://example.com",
+        requestBodyValues: {},
+        statusCode: 429,
+        responseHeaders: { "content-type": "application/json" },
+        isRetryable: false,
+      }),
+      { providerID: "test" },
+    )
+    expect(MessageV2.ContextOverflowError.isInstance(result)).toBe(false)
+    expect(MessageV2.APIError.isInstance(result)).toBe(true)
+  })
+
   test("serializes unknown inputs", () => {
     const result = MessageV2.fromError(123, { providerID: "test" })