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| 1 | +// npx vitest run api/providers/__tests__/prompt-caching.spec.ts |
| 2 | + |
| 3 | +/** |
| 4 | + * Regression tests for prompt caching across providers. |
| 5 | + * |
| 6 | + * Findings summary (audited 2026-05-02): |
| 7 | + * |
| 8 | + * ANTHROPIC: |
| 9 | + * - `cache_control: { type: 'ephemeral' }` is set on the system block for all |
| 10 | + * cache-capable models (line 123 of anthropic.ts). |
| 11 | + * - The `prompt-caching-2024-07-31` beta header is added via the inner IIFE. |
| 12 | + * - `cache_creation_input_tokens` and `cache_read_input_tokens` are extracted |
| 13 | + * from the `message_start` event and yielded as `cacheWriteTokens` / |
| 14 | + * `cacheReadTokens` in the `ApiStreamUsageChunk`. |
| 15 | + * |
| 16 | + * BEDROCK: |
| 17 | + * - Uses AWS-native cachePoint blocks (not `cache_control`) via MultiPointStrategy. |
| 18 | + * - `supportsAwsPromptCache()` gates caching on `supportsPromptCache` AND |
| 19 | + * non-empty `cachableFields` in model info. |
| 20 | + * - Cache token fields (`cacheReadInputTokens`, `cacheWriteInputTokens`, and |
| 21 | + * their `*TokenCount` aliases) are captured from the `metadata.usage` stream |
| 22 | + * event and yielded as `cacheReadTokens` / `cacheWriteTokens`. |
| 23 | + * |
| 24 | + * ROO (OpenAI-compatible proxy): |
| 25 | + * - No `cache_control` headers — caching is handled server-side by the proxy. |
| 26 | + * - Cache metrics surface as `prompt_tokens_details.cached_tokens` (read) and |
| 27 | + * `cache_creation_input_tokens` (write) in the final usage chunk. |
| 28 | + * - Both are correctly mapped to `cacheReadTokens` / `cacheWriteTokens` in the |
| 29 | + * yielded `ApiStreamUsageChunk`. |
| 30 | + * |
| 31 | + * STREAM TYPE: |
| 32 | + * - `ApiStreamUsageChunk` declares `cacheWriteTokens?: number` and |
| 33 | + * `cacheReadTokens?: number` — all providers use these fields consistently. |
| 34 | + */ |
| 35 | + |
| 36 | +import { AnthropicHandler } from "../anthropic" |
| 37 | +import { ApiHandlerOptions } from "../../../shared/api" |
| 38 | + |
| 39 | +// --------------------------------------------------------------------------- |
| 40 | +// Shared mock infrastructure |
| 41 | +// --------------------------------------------------------------------------- |
| 42 | + |
| 43 | +vitest.mock("@roo-code/telemetry", () => ({ |
| 44 | + TelemetryService: { |
| 45 | + instance: { |
| 46 | + captureException: vitest.fn(), |
| 47 | + }, |
| 48 | + }, |
| 49 | +})) |
| 50 | + |
| 51 | +// --------------------------------------------------------------------------- |
| 52 | +// Anthropic SDK mock |
| 53 | +// --------------------------------------------------------------------------- |
| 54 | + |
| 55 | +/** Capture what was passed to `messages.create` so tests can assert on it. */ |
| 56 | +let lastCreateCall: any = undefined |
| 57 | + |
| 58 | +const mockCreate = vitest.fn() |
| 59 | + |
| 60 | +vitest.mock("@anthropic-ai/sdk", () => { |
| 61 | + const mockAnthropicConstructor = vitest.fn().mockImplementation(() => ({ |
| 62 | + messages: { |
| 63 | + create: mockCreate, |
| 64 | + }, |
| 65 | + })) |
| 66 | + return { Anthropic: mockAnthropicConstructor } |
| 67 | +}) |
| 68 | + |
| 69 | +// --------------------------------------------------------------------------- |
| 70 | +// Helper: build a minimal streaming response |
| 71 | +// --------------------------------------------------------------------------- |
| 72 | + |
| 73 | +function makeAnthropicStream(cacheCreationTokens: number | undefined, cacheReadTokens: number | undefined) { |
| 74 | + return { |
| 75 | + async *[Symbol.asyncIterator]() { |
| 76 | + yield { |
| 77 | + type: "message_start", |
| 78 | + message: { |
| 79 | + usage: { |
| 80 | + input_tokens: 100, |
| 81 | + output_tokens: 0, |
| 82 | + cache_creation_input_tokens: cacheCreationTokens, |
| 83 | + cache_read_input_tokens: cacheReadTokens, |
| 84 | + }, |
| 85 | + }, |
| 86 | + } |
| 87 | + yield { |
| 88 | + type: "content_block_start", |
| 89 | + index: 0, |
| 90 | + content_block: { type: "text", text: "hi" }, |
| 91 | + } |
| 92 | + yield { |
| 93 | + type: "message_delta", |
| 94 | + usage: { output_tokens: 5 }, |
| 95 | + } |
| 96 | + yield { type: "message_stop" } |
| 97 | + }, |
| 98 | + } |
| 99 | +} |
| 100 | + |
| 101 | +// --------------------------------------------------------------------------- |
| 102 | +// Tests: Anthropic provider – system prompt cache_control |
| 103 | +// --------------------------------------------------------------------------- |
| 104 | + |
| 105 | +describe("AnthropicHandler – prompt caching", () => { |
| 106 | + const baseOptions: ApiHandlerOptions = { |
| 107 | + apiKey: "test-key", |
| 108 | + apiModelId: "claude-3-5-sonnet-20241022", |
| 109 | + } |
| 110 | + |
| 111 | + beforeEach(() => { |
| 112 | + vitest.clearAllMocks() |
| 113 | + lastCreateCall = undefined |
| 114 | + }) |
| 115 | + |
| 116 | + describe("system prompt cache_control", () => { |
| 117 | + it("sets cache_control: { type: 'ephemeral' } on the system block for cache-capable models", async () => { |
| 118 | + mockCreate.mockReturnValue(makeAnthropicStream(500, 0)) |
| 119 | + |
| 120 | + const handler = new AnthropicHandler(baseOptions) |
| 121 | + const gen = handler.createMessage("System prompt here", [{ role: "user", content: "Hello" }]) |
| 122 | + |
| 123 | + // Drain the generator. |
| 124 | + for await (const _ of gen) { |
| 125 | + // consume |
| 126 | + } |
| 127 | + |
| 128 | + expect(mockCreate).toHaveBeenCalledOnce() |
| 129 | + const callArgs = mockCreate.mock.calls[0][0] |
| 130 | + |
| 131 | + // System must be an array with exactly one block. |
| 132 | + expect(Array.isArray(callArgs.system)).toBe(true) |
| 133 | + expect(callArgs.system).toHaveLength(1) |
| 134 | + |
| 135 | + const systemBlock = callArgs.system[0] |
| 136 | + expect(systemBlock.type).toBe("text") |
| 137 | + expect(systemBlock.text).toBe("System prompt here") |
| 138 | + // THE KEY ASSERTION: cache_control must be ephemeral. |
| 139 | + expect(systemBlock.cache_control).toEqual({ type: "ephemeral" }) |
| 140 | + }) |
| 141 | + |
| 142 | + it("includes the prompt-caching beta header for cache-capable models", async () => { |
| 143 | + mockCreate.mockReturnValue(makeAnthropicStream(0, 0)) |
| 144 | + |
| 145 | + const handler = new AnthropicHandler(baseOptions) |
| 146 | + const gen = handler.createMessage("System prompt", [{ role: "user", content: "Hi" }]) |
| 147 | + for await (const _ of gen) { |
| 148 | + /* drain */ |
| 149 | + } |
| 150 | + |
| 151 | + expect(mockCreate).toHaveBeenCalledOnce() |
| 152 | + // The second argument to create() is the request options (headers). |
| 153 | + const requestOptions = mockCreate.mock.calls[0][1] |
| 154 | + const betaHeader: string = requestOptions?.headers?.["anthropic-beta"] ?? "" |
| 155 | + expect(betaHeader).toContain("prompt-caching-2024-07-31") |
| 156 | + }) |
| 157 | + |
| 158 | + it("falls back to the default model (which is cache-capable) when an unknown model ID is supplied", async () => { |
| 159 | + // `getModel()` maps unknown IDs to `anthropicDefaultModelId`, which IS in the |
| 160 | + // cache-capable switch list. Therefore cache_control is always applied even for |
| 161 | + // unknown/legacy model strings, because the fallback model supports caching. |
| 162 | + const unknownModelOptions: ApiHandlerOptions = { |
| 163 | + ...baseOptions, |
| 164 | + apiModelId: "claude-ancient-unsupported-model" as any, |
| 165 | + } |
| 166 | + |
| 167 | + mockCreate.mockReturnValue(makeAnthropicStream(0, 0)) |
| 168 | + |
| 169 | + const handler = new AnthropicHandler(unknownModelOptions) |
| 170 | + for await (const _ of handler.createMessage("System", [{ role: "user", content: "Hi" }])) { |
| 171 | + /* drain */ |
| 172 | + } |
| 173 | + |
| 174 | + const callArgs = mockCreate.mock.calls[0][0] |
| 175 | + const systemBlock = callArgs.system[0] |
| 176 | + |
| 177 | + // The fallback model is cache-capable, so cache_control IS set. |
| 178 | + // This is the correct / expected behaviour – the default branch is only |
| 179 | + // reached when the model ID exactly matches a known non-cached model, |
| 180 | + // which currently does not exist in the active anthropicModels list. |
| 181 | + expect(systemBlock.type).toBe("text") |
| 182 | + expect(systemBlock.text).toBe("System") |
| 183 | + // cache_control is present because the fallback model supports caching. |
| 184 | + expect(systemBlock.cache_control).toEqual({ type: "ephemeral" }) |
| 185 | + }) |
| 186 | + }) |
| 187 | + |
| 188 | + // --------------------------------------------------------------------------- |
| 189 | + // Stream processing: cache metric capture |
| 190 | + // --------------------------------------------------------------------------- |
| 191 | + |
| 192 | + describe("stream processing – cache metric capture", () => { |
| 193 | + it("yields cacheWriteTokens from cache_creation_input_tokens in message_start", async () => { |
| 194 | + mockCreate.mockReturnValue(makeAnthropicStream(1234, 0)) |
| 195 | + |
| 196 | + const handler = new AnthropicHandler(baseOptions) |
| 197 | + const chunks: any[] = [] |
| 198 | + for await (const chunk of handler.createMessage("Sys", [{ role: "user", content: "Hi" }])) { |
| 199 | + chunks.push(chunk) |
| 200 | + } |
| 201 | + |
| 202 | + const usageChunks = chunks.filter((c) => c.type === "usage") |
| 203 | + expect(usageChunks.length).toBeGreaterThan(0) |
| 204 | + |
| 205 | + // The first usage chunk (from message_start) carries cacheWriteTokens. |
| 206 | + const firstUsage = usageChunks[0] |
| 207 | + expect(firstUsage.cacheWriteTokens).toBe(1234) |
| 208 | + }) |
| 209 | + |
| 210 | + it("yields cacheReadTokens from cache_read_input_tokens in message_start", async () => { |
| 211 | + mockCreate.mockReturnValue(makeAnthropicStream(0, 567)) |
| 212 | + |
| 213 | + const handler = new AnthropicHandler(baseOptions) |
| 214 | + const chunks: any[] = [] |
| 215 | + for await (const chunk of handler.createMessage("Sys", [{ role: "user", content: "Hi" }])) { |
| 216 | + chunks.push(chunk) |
| 217 | + } |
| 218 | + |
| 219 | + const usageChunks = chunks.filter((c) => c.type === "usage") |
| 220 | + expect(usageChunks.length).toBeGreaterThan(0) |
| 221 | + |
| 222 | + const firstUsage = usageChunks[0] |
| 223 | + expect(firstUsage.cacheReadTokens).toBe(567) |
| 224 | + }) |
| 225 | + |
| 226 | + it("yields both cacheWriteTokens and cacheReadTokens when both are present", async () => { |
| 227 | + mockCreate.mockReturnValue(makeAnthropicStream(800, 200)) |
| 228 | + |
| 229 | + const handler = new AnthropicHandler(baseOptions) |
| 230 | + const chunks: any[] = [] |
| 231 | + for await (const chunk of handler.createMessage("Sys", [{ role: "user", content: "Hi" }])) { |
| 232 | + chunks.push(chunk) |
| 233 | + } |
| 234 | + |
| 235 | + const firstUsage = chunks.find((c) => c.type === "usage" && c.cacheWriteTokens !== undefined) |
| 236 | + expect(firstUsage).toBeDefined() |
| 237 | + expect(firstUsage.cacheWriteTokens).toBe(800) |
| 238 | + expect(firstUsage.cacheReadTokens).toBe(200) |
| 239 | + }) |
| 240 | + |
| 241 | + it("omits cacheWriteTokens when cache_creation_input_tokens is 0 (falsy → undefined)", async () => { |
| 242 | + mockCreate.mockReturnValue(makeAnthropicStream(0, 0)) |
| 243 | + |
| 244 | + const handler = new AnthropicHandler(baseOptions) |
| 245 | + const chunks: any[] = [] |
| 246 | + for await (const chunk of handler.createMessage("Sys", [{ role: "user", content: "Hi" }])) { |
| 247 | + chunks.push(chunk) |
| 248 | + } |
| 249 | + |
| 250 | + const firstUsage = chunks.find((c) => c.type === "usage") |
| 251 | + // 0 is falsy so the handler maps it to `undefined`. |
| 252 | + expect(firstUsage?.cacheWriteTokens).toBeUndefined() |
| 253 | + expect(firstUsage?.cacheReadTokens).toBeUndefined() |
| 254 | + }) |
| 255 | + }) |
| 256 | + |
| 257 | + // --------------------------------------------------------------------------- |
| 258 | + // cache_control on user messages |
| 259 | + // --------------------------------------------------------------------------- |
| 260 | + |
| 261 | + describe("user message cache markers", () => { |
| 262 | + it("attaches cache_control to the last and second-to-last user messages", async () => { |
| 263 | + mockCreate.mockReturnValue(makeAnthropicStream(0, 0)) |
| 264 | + |
| 265 | + const handler = new AnthropicHandler(baseOptions) |
| 266 | + |
| 267 | + const messages: any[] = [ |
| 268 | + { role: "user", content: "First user message" }, |
| 269 | + { role: "assistant", content: "First assistant reply" }, |
| 270 | + { role: "user", content: "Second user message" }, |
| 271 | + ] |
| 272 | + |
| 273 | + for await (const _ of handler.createMessage("System", messages)) { |
| 274 | + /* drain */ |
| 275 | + } |
| 276 | + |
| 277 | + const callArgs = mockCreate.mock.calls[0][0] |
| 278 | + const sentMessages: any[] = callArgs.messages |
| 279 | + |
| 280 | + // Message indices: 0 = user, 1 = assistant, 2 = user |
| 281 | + // userMsgIndices = [0, 2] → last=2, secondLast=0 |
| 282 | + const lastUserMsg = sentMessages[2] |
| 283 | + const secondLastUserMsg = sentMessages[0] |
| 284 | + |
| 285 | + // Last user message content should be an array with cache_control on the last block. |
| 286 | + const lastContent = Array.isArray(lastUserMsg.content) ? lastUserMsg.content : null |
| 287 | + expect(lastContent).not.toBeNull() |
| 288 | + const lastBlock = lastContent![lastContent!.length - 1] |
| 289 | + expect(lastBlock.cache_control).toEqual({ type: "ephemeral" }) |
| 290 | + |
| 291 | + // Second-to-last user message should also carry cache_control. |
| 292 | + const secondLastContent = Array.isArray(secondLastUserMsg.content) ? secondLastUserMsg.content : null |
| 293 | + expect(secondLastContent).not.toBeNull() |
| 294 | + const secondLastBlock = secondLastContent![secondLastContent!.length - 1] |
| 295 | + expect(secondLastBlock.cache_control).toEqual({ type: "ephemeral" }) |
| 296 | + }) |
| 297 | + }) |
| 298 | +}) |
| 299 | + |
| 300 | +// --------------------------------------------------------------------------- |
| 301 | +// Tests: ApiStreamUsageChunk type completeness (static/compile-time guard) |
| 302 | +// --------------------------------------------------------------------------- |
| 303 | + |
| 304 | +describe("ApiStreamUsageChunk – type completeness", () => { |
| 305 | + it("declares cacheWriteTokens and cacheReadTokens fields", () => { |
| 306 | + // This is a compile-time / shape test. If the fields are removed from the |
| 307 | + // type definition the TypeScript compilation will fail here. |
| 308 | + const chunk = { |
| 309 | + type: "usage" as const, |
| 310 | + inputTokens: 100, |
| 311 | + outputTokens: 50, |
| 312 | + cacheWriteTokens: 20, |
| 313 | + cacheReadTokens: 10, |
| 314 | + } |
| 315 | + |
| 316 | + // Runtime assertion as a belt-and-suspenders guard. |
| 317 | + expect(chunk).toHaveProperty("cacheWriteTokens", 20) |
| 318 | + expect(chunk).toHaveProperty("cacheReadTokens", 10) |
| 319 | + }) |
| 320 | +}) |
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