test(llm): cover OpenAI-compatible Chat parity

packages/llm/test/fixtures/recordings/openai-compatible-chat/deepseek-streams-text.json

@@ -0,0 +1 @@
+{"version":1,"interactions":[{"request":{"method":"POST","url":"https://api.deepseek.com/v1/chat/completions","headers":{"content-type":"application/json"},"body":"{\"model\":\"deepseek-chat\",\"messages\":[{\"role\":\"system\",\"content\":\"You are concise.\"},{\"role\":\"user\",\"content\":\"Reply with exactly: Hello!\"}],\"stream\":true,\"max_tokens\":20,\"temperature\":0}"},"response":{"status":200,"headers":{"content-type":"text/event-stream; charset=utf-8"},"body":"data: {\"id\":\"37be8034-f5e7-41e4-8ee7-39e0b5c613a2\",\"object\":\"chat.completion.chunk\",\"created\":1777218434,\"model\":\"deepseek-v4-flash\",\"system_fingerprint\":\"fp_058df29938_prod0820_fp8_kvcache_20260402\",\"choices\":[{\"index\":0,\"delta\":{\"role\":\"assistant\",\"content\":\"\"},\"logprobs\":null,\"finish_reason\":null}]}\n\ndata: {\"id\":\"37be8034-f5e7-41e4-8ee7-39e0b5c613a2\",\"object\":\"chat.completion.chunk\",\"created\":1777218434,\"model\":\"deepseek-v4-flash\",\"system_fingerprint\":\"fp_058df29938_prod0820_fp8_kvcache_20260402\",\"choices\":[{\"index\":0,\"delta\":{\"content\":\"Hello\"},\"logprobs\":null,\"finish_reason\":null}]}\n\ndata: {\"id\":\"37be8034-f5e7-41e4-8ee7-39e0b5c613a2\",\"object\":\"chat.completion.chunk\",\"created\":1777218434,\"model\":\"deepseek-v4-flash\",\"system_fingerprint\":\"fp_058df29938_prod0820_fp8_kvcache_20260402\",\"choices\":[{\"index\":0,\"delta\":{\"content\":\"!\"},\"logprobs\":null,\"finish_reason\":null}]}\n\ndata: {\"id\":\"37be8034-f5e7-41e4-8ee7-39e0b5c613a2\",\"object\":\"chat.completion.chunk\",\"created\":1777218434,\"model\":\"deepseek-v4-flash\",\"system_fingerprint\":\"fp_058df29938_prod0820_fp8_kvcache_20260402\",\"choices\":[{\"index\":0,\"delta\":{\"content\":\"\"},\"logprobs\":null,\"finish_reason\":\"stop\"}],\"usage\":{\"prompt_tokens\":14,\"completion_tokens\":2,\"total_tokens\":16,\"prompt_tokens_details\":{\"cached_tokens\":0},\"prompt_cache_hit_tokens\":0,\"prompt_cache_miss_tokens\":14}}\n\ndata: [DONE]\n\n"}}]}

packages/llm/test/provider/openai-compatible-chat.recorded.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect } from "bun:test"
+import { Effect } from "effect"
+import { LLM } from "../../src"
+import { client } from "../../src/adapter"
+import { OpenAICompatibleChat } from "../../src/provider/openai-compatible-chat"
+import { recordedTests } from "../recorded-test"
+
+const deepseekModel = OpenAICompatibleChat.deepseek({
+  id: "deepseek-chat",
+  apiKey: process.env.DEEPSEEK_API_KEY ?? "fixture",
+})
+
+const deepseekRequest = LLM.request({
+  id: "recorded_deepseek_text",
+  model: deepseekModel,
+  system: "You are concise.",
+  prompt: "Reply with exactly: Hello!",
+  generation: { maxTokens: 20, temperature: 0 },
+})
+
+const recorded = recordedTests({ prefix: "openai-compatible-chat" })
+const llm = client({ adapters: [OpenAICompatibleChat.adapter] })
+
+describe("OpenAI-compatible Chat recorded", () => {
+  recorded.effect.with("deepseek streams text", { requires: ["DEEPSEEK_API_KEY"] }, () =>
+    Effect.gen(function* () {
+      const response = yield* llm.generate(deepseekRequest)
+
+      expect(LLM.outputText(response)).toMatch(/^Hello!?$/)
+      expect(response.events.at(-1)).toMatchObject({ type: "request-finish", reason: "stop" })
+    }),
+  )
+})

packages/llm/test/provider/openai-compatible-chat.test.ts

@@ -124,6 +124,72 @@ describe("OpenAI-compatible Chat adapter", () => {
     }),
   )
 
+  it.effect("matches AI SDK compatible basic request body fixture", () =>
+    Effect.gen(function* () {
+      const prepared = yield* client({ adapters: [OpenAICompatibleChat.adapter] }).prepare(request)
+
+      expect(prepared.target).toEqual({
+        model: "deepseek-chat",
+        messages: [
+          { role: "system", content: "You are concise." },
+          { role: "user", content: "Say hello." },
+        ],
+        stream: true,
+        max_tokens: 20,
+        temperature: 0,
+      })
+    }),
+  )
+
+  it.effect("matches AI SDK compatible tool request body fixture", () =>
+    Effect.gen(function* () {
+      const prepared = yield* client({ adapters: [OpenAICompatibleChat.adapter] }).prepare(
+        LLM.request({
+          id: "req_tool_parity",
+          model,
+          tools: [{
+            name: "lookup",
+            description: "Lookup data",
+            inputSchema: { type: "object", properties: { query: { type: "string" } }, required: ["query"] },
+          }],
+          toolChoice: "lookup",
+          messages: [
+            LLM.user("What is the weather?"),
+            LLM.assistant([LLM.toolCall({ id: "call_1", name: "lookup", input: { query: "weather" } })]),
+            LLM.toolMessage({ id: "call_1", name: "lookup", result: { forecast: "sunny" } }),
+          ],
+        }),
+      )
+
+      expect(prepared.target).toEqual({
+        model: "deepseek-chat",
+        messages: [
+          { role: "user", content: "What is the weather?" },
+          {
+            role: "assistant",
+            content: null,
+            tool_calls: [{
+              id: "call_1",
+              type: "function",
+              function: { name: "lookup", arguments: '{"query":"weather"}' },
+            }],
+          },
+          { role: "tool", tool_call_id: "call_1", content: '{"forecast":"sunny"}' },
+        ],
+        tools: [{
+          type: "function",
+          function: {
+            name: "lookup",
+            description: "Lookup data",
+            parameters: { type: "object", properties: { query: { type: "string" } }, required: ["query"] },
+          },
+        }],
+        tool_choice: { type: "function", function: { name: "lookup" } },
+        stream: true,
+      })
+    }),
+  )
+
   it.effect("posts to the configured compatible endpoint and parses text usage", () =>
     Effect.gen(function* () {
       const response = yield* client({