|
| 1 | +package anthropic |
| 2 | + |
| 3 | +import ( |
| 4 | + "encoding/json" |
| 5 | + "testing" |
| 6 | + |
| 7 | + "github.com/anthropics/anthropic-sdk-go" |
| 8 | + "github.com/openai/openai-go" |
| 9 | + "github.com/stretchr/testify/assert" |
| 10 | + "github.com/stretchr/testify/require" |
| 11 | +) |
| 12 | + |
| 13 | +// These tests verify that the OpenAI ↔ Anthropic conversion layer produces |
| 14 | +// JSON output that is wire-compatible with the respective official SDKs. |
| 15 | +// They serve as a regression guard against schema drift when either SDK is |
| 16 | +// upgraded or when internal conversion logic is refactored. |
| 17 | + |
| 18 | +func TestRoundTrip_SimpleRequest(t *testing.T) { |
| 19 | + orig := &openai.ChatCompletionNewParams{ |
| 20 | + Model: "claude-sonnet-4-5", |
| 21 | + Messages: []openai.ChatCompletionMessageParamUnion{ |
| 22 | + {OfUser: &openai.ChatCompletionUserMessageParam{ |
| 23 | + Content: openai.ChatCompletionUserMessageParamContentUnion{ |
| 24 | + OfString: openai.String("Explain photosynthesis."), |
| 25 | + }, |
| 26 | + }}, |
| 27 | + }, |
| 28 | + Temperature: openai.Float(0.5), |
| 29 | + } |
| 30 | + |
| 31 | + anthropicBody, err := ToAnthropicRequestBody(orig) |
| 32 | + require.NoError(t, err) |
| 33 | + |
| 34 | + var parsed anthropic.MessageNewParams |
| 35 | + require.NoError(t, json.Unmarshal(anthropicBody, &parsed)) |
| 36 | + |
| 37 | + assert.Equal(t, anthropic.Model("claude-sonnet-4-5"), parsed.Model) |
| 38 | + assert.Equal(t, DefaultMaxTokens, parsed.MaxTokens) |
| 39 | + require.Len(t, parsed.Messages, 1) |
| 40 | + assert.Equal(t, anthropic.MessageParamRoleUser, parsed.Messages[0].Role) |
| 41 | +} |
| 42 | + |
| 43 | +func TestRoundTrip_SystemSeparation(t *testing.T) { |
| 44 | + orig := &openai.ChatCompletionNewParams{ |
| 45 | + Model: "claude-sonnet-4-5", |
| 46 | + Messages: []openai.ChatCompletionMessageParamUnion{ |
| 47 | + {OfSystem: &openai.ChatCompletionSystemMessageParam{ |
| 48 | + Content: openai.ChatCompletionSystemMessageParamContentUnion{ |
| 49 | + OfString: openai.String("Be concise."), |
| 50 | + }, |
| 51 | + }}, |
| 52 | + {OfUser: &openai.ChatCompletionUserMessageParam{ |
| 53 | + Content: openai.ChatCompletionUserMessageParamContentUnion{ |
| 54 | + OfString: openai.String("Hi"), |
| 55 | + }, |
| 56 | + }}, |
| 57 | + }, |
| 58 | + } |
| 59 | + |
| 60 | + body, err := ToAnthropicRequestBody(orig) |
| 61 | + require.NoError(t, err) |
| 62 | + |
| 63 | + var parsed anthropic.MessageNewParams |
| 64 | + require.NoError(t, json.Unmarshal(body, &parsed)) |
| 65 | + |
| 66 | + require.Len(t, parsed.System, 1) |
| 67 | + assert.Equal(t, "Be concise.", parsed.System[0].Text) |
| 68 | + require.Len(t, parsed.Messages, 1, "system must not appear in messages array") |
| 69 | +} |
| 70 | + |
| 71 | +func TestRoundTrip_MaxTokensVariants(t *testing.T) { |
| 72 | + tests := []struct { |
| 73 | + name string |
| 74 | + req *openai.ChatCompletionNewParams |
| 75 | + expected int64 |
| 76 | + }{ |
| 77 | + { |
| 78 | + name: "MaxCompletionTokens takes priority", |
| 79 | + req: &openai.ChatCompletionNewParams{ |
| 80 | + Model: "claude-sonnet-4-5", |
| 81 | + MaxCompletionTokens: openai.Int(512), |
| 82 | + MaxTokens: openai.Int(1024), |
| 83 | + Messages: simpleUserMsg("hi"), |
| 84 | + }, |
| 85 | + expected: 512, |
| 86 | + }, |
| 87 | + { |
| 88 | + name: "fallback to MaxTokens", |
| 89 | + req: &openai.ChatCompletionNewParams{ |
| 90 | + Model: "claude-sonnet-4-5", |
| 91 | + MaxTokens: openai.Int(2048), |
| 92 | + Messages: simpleUserMsg("hi"), |
| 93 | + }, |
| 94 | + expected: 2048, |
| 95 | + }, |
| 96 | + { |
| 97 | + name: "default when neither set", |
| 98 | + req: &openai.ChatCompletionNewParams{ |
| 99 | + Model: "claude-sonnet-4-5", |
| 100 | + Messages: simpleUserMsg("hi"), |
| 101 | + }, |
| 102 | + expected: DefaultMaxTokens, |
| 103 | + }, |
| 104 | + } |
| 105 | + |
| 106 | + for _, tt := range tests { |
| 107 | + t.Run(tt.name, func(t *testing.T) { |
| 108 | + body, err := ToAnthropicRequestBody(tt.req) |
| 109 | + require.NoError(t, err) |
| 110 | + |
| 111 | + var parsed anthropic.MessageNewParams |
| 112 | + require.NoError(t, json.Unmarshal(body, &parsed)) |
| 113 | + assert.Equal(t, tt.expected, parsed.MaxTokens) |
| 114 | + }) |
| 115 | + } |
| 116 | +} |
| 117 | + |
| 118 | +func TestResponse_StopReasonMapping(t *testing.T) { |
| 119 | + tests := []struct { |
| 120 | + anthropicReason anthropic.StopReason |
| 121 | + expectedOpenAI string |
| 122 | + }{ |
| 123 | + {anthropic.StopReasonEndTurn, "stop"}, |
| 124 | + {anthropic.StopReasonMaxTokens, "length"}, |
| 125 | + {anthropic.StopReasonToolUse, "tool_calls"}, |
| 126 | + {"unknown_future_reason", "stop"}, |
| 127 | + } |
| 128 | + |
| 129 | + for _, tt := range tests { |
| 130 | + t.Run(string(tt.anthropicReason), func(t *testing.T) { |
| 131 | + resp := anthropic.Message{ |
| 132 | + ID: "msg_test", |
| 133 | + Content: []anthropic.ContentBlockUnion{{Type: "text", Text: "ok"}}, |
| 134 | + StopReason: tt.anthropicReason, |
| 135 | + Usage: anthropic.Usage{InputTokens: 1, OutputTokens: 1}, |
| 136 | + } |
| 137 | + |
| 138 | + raw, err := json.Marshal(resp) |
| 139 | + require.NoError(t, err) |
| 140 | + |
| 141 | + out, err := ToOpenAIResponseBody(raw, "claude-sonnet-4-5") |
| 142 | + require.NoError(t, err) |
| 143 | + |
| 144 | + var oai openai.ChatCompletion |
| 145 | + require.NoError(t, json.Unmarshal(out, &oai)) |
| 146 | + assert.Equal(t, tt.expectedOpenAI, oai.Choices[0].FinishReason) |
| 147 | + }) |
| 148 | + } |
| 149 | +} |
| 150 | + |
| 151 | +func TestResponse_UsageMapping(t *testing.T) { |
| 152 | + resp := anthropic.Message{ |
| 153 | + ID: "msg_usage", |
| 154 | + Content: []anthropic.ContentBlockUnion{{Type: "text", Text: "hi"}}, |
| 155 | + StopReason: anthropic.StopReasonEndTurn, |
| 156 | + Usage: anthropic.Usage{InputTokens: 42, OutputTokens: 17}, |
| 157 | + } |
| 158 | + |
| 159 | + raw, err := json.Marshal(resp) |
| 160 | + require.NoError(t, err) |
| 161 | + |
| 162 | + out, err := ToOpenAIResponseBody(raw, "test-model") |
| 163 | + require.NoError(t, err) |
| 164 | + |
| 165 | + var oai openai.ChatCompletion |
| 166 | + require.NoError(t, json.Unmarshal(out, &oai)) |
| 167 | + |
| 168 | + assert.Equal(t, int64(42), oai.Usage.PromptTokens) |
| 169 | + assert.Equal(t, int64(17), oai.Usage.CompletionTokens) |
| 170 | + assert.Equal(t, int64(59), oai.Usage.TotalTokens) |
| 171 | +} |
| 172 | + |
| 173 | +func TestResponse_OutputIsValidOpenAIJSON(t *testing.T) { |
| 174 | + resp := anthropic.Message{ |
| 175 | + ID: "msg_valid", |
| 176 | + Role: "assistant", |
| 177 | + Content: []anthropic.ContentBlockUnion{ |
| 178 | + {Type: "text", Text: "Hello world"}, |
| 179 | + }, |
| 180 | + StopReason: anthropic.StopReasonEndTurn, |
| 181 | + Usage: anthropic.Usage{InputTokens: 5, OutputTokens: 3}, |
| 182 | + } |
| 183 | + raw, err := json.Marshal(resp) |
| 184 | + require.NoError(t, err) |
| 185 | + |
| 186 | + out, err := ToOpenAIResponseBody(raw, "claude-sonnet-4-5") |
| 187 | + require.NoError(t, err) |
| 188 | + |
| 189 | + var oai openai.ChatCompletion |
| 190 | + require.NoError(t, json.Unmarshal(out, &oai), |
| 191 | + "output must unmarshal cleanly into the official openai.ChatCompletion type") |
| 192 | + |
| 193 | + assert.Equal(t, "chat.completion", string(oai.Object)) |
| 194 | + assert.Equal(t, "msg_valid", oai.ID) |
| 195 | + assert.Equal(t, "claude-sonnet-4-5", oai.Model) |
| 196 | + require.Len(t, oai.Choices, 1) |
| 197 | + assert.Equal(t, "assistant", string(oai.Choices[0].Message.Role)) |
| 198 | + assert.Equal(t, "Hello world", oai.Choices[0].Message.Content) |
| 199 | + assert.NotZero(t, oai.Created) |
| 200 | +} |
| 201 | + |
| 202 | +func TestRequest_EmptyMessagesRejected(t *testing.T) { |
| 203 | + req := &openai.ChatCompletionNewParams{ |
| 204 | + Model: "claude-sonnet-4-5", |
| 205 | + Messages: nil, |
| 206 | + } |
| 207 | + |
| 208 | + body, err := ToAnthropicRequestBody(req) |
| 209 | + require.NoError(t, err) |
| 210 | + |
| 211 | + var parsed anthropic.MessageNewParams |
| 212 | + require.NoError(t, json.Unmarshal(body, &parsed)) |
| 213 | + assert.Empty(t, parsed.Messages) |
| 214 | +} |
| 215 | + |
| 216 | +func TestResponse_EmptyContentBlocks(t *testing.T) { |
| 217 | + resp := anthropic.Message{ |
| 218 | + ID: "msg_empty", |
| 219 | + Content: []anthropic.ContentBlockUnion{}, |
| 220 | + StopReason: anthropic.StopReasonEndTurn, |
| 221 | + Usage: anthropic.Usage{InputTokens: 1, OutputTokens: 0}, |
| 222 | + } |
| 223 | + raw, err := json.Marshal(resp) |
| 224 | + require.NoError(t, err) |
| 225 | + |
| 226 | + out, err := ToOpenAIResponseBody(raw, "model") |
| 227 | + require.NoError(t, err) |
| 228 | + |
| 229 | + var oai openai.ChatCompletion |
| 230 | + require.NoError(t, json.Unmarshal(out, &oai)) |
| 231 | + assert.Empty(t, oai.Choices[0].Message.Content) |
| 232 | +} |
| 233 | + |
| 234 | +func TestRequest_StopSequences(t *testing.T) { |
| 235 | + t.Run("string array", func(t *testing.T) { |
| 236 | + req := &openai.ChatCompletionNewParams{ |
| 237 | + Model: "claude-sonnet-4-5", |
| 238 | + Messages: simpleUserMsg("hi"), |
| 239 | + Stop: openai.ChatCompletionNewParamsStopUnion{ |
| 240 | + OfStringArray: []string{"END", "DONE"}, |
| 241 | + }, |
| 242 | + } |
| 243 | + |
| 244 | + body, err := ToAnthropicRequestBody(req) |
| 245 | + require.NoError(t, err) |
| 246 | + |
| 247 | + var parsed anthropic.MessageNewParams |
| 248 | + require.NoError(t, json.Unmarshal(body, &parsed)) |
| 249 | + assert.Equal(t, []string{"END", "DONE"}, parsed.StopSequences) |
| 250 | + }) |
| 251 | + |
| 252 | + t.Run("single string", func(t *testing.T) { |
| 253 | + req := &openai.ChatCompletionNewParams{ |
| 254 | + Model: "claude-sonnet-4-5", |
| 255 | + Messages: simpleUserMsg("hi"), |
| 256 | + Stop: openai.ChatCompletionNewParamsStopUnion{ |
| 257 | + OfString: openai.String("STOP"), |
| 258 | + }, |
| 259 | + } |
| 260 | + |
| 261 | + body, err := ToAnthropicRequestBody(req) |
| 262 | + require.NoError(t, err) |
| 263 | + |
| 264 | + var parsed anthropic.MessageNewParams |
| 265 | + require.NoError(t, json.Unmarshal(body, &parsed)) |
| 266 | + assert.Equal(t, []string{"STOP"}, parsed.StopSequences) |
| 267 | + }) |
| 268 | +} |
| 269 | + |
| 270 | +// simpleUserMsg builds a minimal message slice for tests. |
| 271 | +func simpleUserMsg(text string) []openai.ChatCompletionMessageParamUnion { |
| 272 | + return []openai.ChatCompletionMessageParamUnion{ |
| 273 | + {OfUser: &openai.ChatCompletionUserMessageParam{ |
| 274 | + Content: openai.ChatCompletionUserMessageParamContentUnion{ |
| 275 | + OfString: openai.String(text), |
| 276 | + }, |
| 277 | + }}, |
| 278 | + } |
| 279 | +} |
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