fix: sanitize surrogates (#25934)

packages/opencode/test/provider/transform.test.ts

@@ -1123,6 +1123,98 @@ describe("ProviderTransform.message - DeepSeek reasoning content", () => {
   })
 })
 
+describe("ProviderTransform.message - surrogate sanitization", () => {
+  const model = {
+    id: "test/test-model",
+    providerID: "test",
+    api: {
+      id: "test-model",
+      url: "https://api.test.com",
+      npm: "@ai-sdk/openai-compatible",
+    },
+    name: "Test Model",
+    capabilities: {
+      temperature: true,
+      reasoning: true,
+      attachment: true,
+      toolcall: true,
+      input: { text: true, audio: false, image: true, video: false, pdf: false },
+      output: { text: true, audio: false, image: false, video: false, pdf: false },
+      interleaved: false,
+    },
+    cost: { input: 0.001, output: 0.002, cache: { read: 0.0001, write: 0.0002 } },
+    limit: { context: 128000, output: 8192 },
+    status: "active",
+    options: {},
+    headers: {},
+  } as any
+
+  test("replaces lone surrogates in model-visible text", () => {
+    const lone = "\uD83D"
+    const valid = "🚀"
+    const sanitized = "<22>"
+    const text = (label: string) => `${label} ${lone} and ${valid}`
+    const expected = (label: string) => `${label} ${sanitized} and ${valid}`
+    const msgs = [
+      { role: "system", content: text("system") },
+      { role: "user", content: text("user string") },
+      {
+        role: "user",
+        content: [
+          { type: "text", text: text("user text") },
+          { type: "image", image: "data:image/png;base64,abcd" },
+        ],
+      },
+      { role: "assistant", content: text("assistant string") },
+      {
+        role: "assistant",
+        content: [
+          { type: "text", text: text("assistant text") },
+          { type: "reasoning", text: text("assistant reasoning") },
+          { type: "tool-call", toolCallId: "call-1", toolName: "Read", input: { filePath: ".opencode/tool/emoji.ts" } },
+          { type: "tool-result", toolCallId: "call-2", toolName: "Read", output: { type: "text", value: text("assistant tool text") } },
+          { type: "tool-result", toolCallId: "call-3", toolName: "Read", output: { type: "error-text", value: text("assistant tool error") } },
+          {
+            type: "tool-result",
+            toolCallId: "call-4",
+            toolName: "Read",
+            output: { type: "content", value: [{ type: "text", text: text("assistant tool content") }] },
+          },
+        ],
+      },
+      {
+        role: "tool",
+        content: [
+          { type: "tool-result", toolCallId: "call-5", toolName: "Read", output: { type: "text", value: text("tool text") } },
+          { type: "tool-result", toolCallId: "call-6", toolName: "Read", output: { type: "error-text", value: text("tool error") } },
+          {
+            type: "tool-result",
+            toolCallId: "call-7",
+            toolName: "Read",
+            output: { type: "content", value: [{ type: "text", text: text("tool content") }] },
+          },
+        ],
+      },
+    ] as any[]
+
+    const result = ProviderTransform.message(msgs, model, {}) as any[]
+
+    expect(result[0].content).toBe(expected("system"))
+    expect(result[1].content).toBe(expected("user string"))
+    expect(result[2].content[0].text).toBe(expected("user text"))
+    expect(result[3].content).toBe(expected("assistant string"))
+    expect(result[4].content[0].text).toBe(expected("assistant text"))
+    expect(result[4].content[1].text).toBe(expected("assistant reasoning"))
+    expect(result[4].content[3].output.value).toBe(expected("assistant tool text"))
+    expect(result[4].content[4].output.value).toBe(expected("assistant tool error"))
+    expect(result[4].content[5].output.value[0].text).toBe(expected("assistant tool content"))
+    expect(result[5].content[0].output.value).toBe(expected("tool text"))
+    expect(result[5].content[1].output.value).toBe(expected("tool error"))
+    expect(result[5].content[2].output.value[0].text).toBe(expected("tool content"))
+    expect(result[2].content[1]).toEqual({ type: "image", image: "data:image/png;base64,abcd" })
+  })
+})
+
 describe("ProviderTransform.message - empty image handling", () => {
   const mockModel = {
     id: "anthropic/claude-3-5-sonnet",
@@ -1993,7 +2085,7 @@ describe("ProviderTransform.message - bedrock caching with non-bedrock providerI
     const msgs = [
       {
         role: "system",
-        content: [{ type: "text", text: "You are a helpful assistant" }],
+        content: "You are a helpful assistant",
       },
       {
         role: "user",
@@ -2007,7 +2099,7 @@ describe("ProviderTransform.message - bedrock caching with non-bedrock providerI
     expect(result[0].providerOptions?.bedrock).toEqual({
       cachePoint: { type: "default" },
     })
-    expect(result[0].content[0].providerOptions?.bedrock).toBeUndefined()
+    expect(result[0].content).toBe("You are a helpful assistant")
   })
 })
 
@@ -2044,7 +2136,7 @@ describe("ProviderTransform.message - cache control on gateway", () => {
     const msgs = [
       {
         role: "system",
-        content: [{ type: "text", text: "You are a helpful assistant" }],
+        content: "You are a helpful assistant",
       },
       {
         role: "user",
@@ -2054,7 +2146,7 @@ describe("ProviderTransform.message - cache control on gateway", () => {
 
     const result = ProviderTransform.message(msgs, model, {}) as any[]
 
-    expect(result[0].content[0].providerOptions).toBeUndefined()
+    expect(result[0].content).toBe("You are a helpful assistant")
     expect(result[0].providerOptions).toBeUndefined()
   })