github--github-mcp-server/pkg/errors/error_test.go

package errors

import (
	"context"
	"fmt"
	"github.com/google/go-github/v89/github"
	"github.com/modelcontextprotocol/go-sdk/mcp"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"net/http"
	"testing"
	"time"
)

func TestGitHubErrorContext(t *testing.T) {
	t.Run("API errors can be added to context and retrieved", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		// Create a mock GitHub response
		resp := &github.Response{
			Response: &http.Response{
				StatusCode: 404,
				Status:     "404 Not Found",
			},
		}
		originalErr := fmt.Errorf("resource not found")

		// When we add an API error to the context
		updatedCtx, err := NewGitHubAPIErrorToCtx(ctx, "failed to fetch resource", resp, originalErr)
		require.NoError(t, err)

		// Then we should be able to retrieve the error from the updated context
		apiErrors, err := GetGitHubAPIErrors(updatedCtx)
		require.NoError(t, err)
		require.Len(t, apiErrors, 1)

		apiError := apiErrors[0]
		assert.Equal(t, "failed to fetch resource", apiError.Message)
		assert.Equal(t, resp, apiError.Response)
		assert.Equal(t, originalErr, apiError.Err)
		assert.Equal(t, "failed to fetch resource: resource not found", apiError.Error())
	})

	t.Run("GraphQL errors can be added to context and retrieved", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		originalErr := fmt.Errorf("GraphQL query failed")

		// When we add a GraphQL error to the context
		graphQLErr := newGitHubGraphQLError("failed to execute mutation", originalErr)
		updatedCtx, err := addGitHubGraphQLErrorToContext(ctx, graphQLErr)
		require.NoError(t, err)

		// Then we should be able to retrieve the error from the updated context
		gqlErrors, err := GetGitHubGraphQLErrors(updatedCtx)
		require.NoError(t, err)
		require.Len(t, gqlErrors, 1)

		gqlError := gqlErrors[0]
		assert.Equal(t, "failed to execute mutation", gqlError.Message)
		assert.Equal(t, originalErr, gqlError.Err)
		assert.Equal(t, "failed to execute mutation: GraphQL query failed", gqlError.Error())
	})

	t.Run("Raw API errors can be added to context and retrieved", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		// Create a mock HTTP response
		resp := &http.Response{
			StatusCode: 404,
			Status:     "404 Not Found",
		}
		originalErr := fmt.Errorf("raw content not found")

		// When we add a raw API error to the context
		rawAPIErr := newGitHubRawAPIError("failed to fetch raw content", resp, originalErr)
		updatedCtx, err := addRawAPIErrorToContext(ctx, rawAPIErr)
		require.NoError(t, err)

		// Then we should be able to retrieve the error from the updated context
		rawErrors, err := GetGitHubRawAPIErrors(updatedCtx)
		require.NoError(t, err)
		require.Len(t, rawErrors, 1)

		rawError := rawErrors[0]
		assert.Equal(t, "failed to fetch raw content", rawError.Message)
		assert.Equal(t, resp, rawError.Response)
		assert.Equal(t, originalErr, rawError.Err)
	})

	t.Run("multiple errors can be accumulated in context", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		// When we add multiple API errors
		resp1 := &github.Response{Response: &http.Response{StatusCode: 404}}
		resp2 := &github.Response{Response: &http.Response{StatusCode: 403}}

		ctx, err := NewGitHubAPIErrorToCtx(ctx, "first error", resp1, fmt.Errorf("not found"))
		require.NoError(t, err)

		ctx, err = NewGitHubAPIErrorToCtx(ctx, "second error", resp2, fmt.Errorf("forbidden"))
		require.NoError(t, err)

		// And add a GraphQL error
		gqlErr := newGitHubGraphQLError("graphql error", fmt.Errorf("query failed"))
		ctx, err = addGitHubGraphQLErrorToContext(ctx, gqlErr)
		require.NoError(t, err)

		// And add a raw API error
		rawErr := newGitHubRawAPIError("raw error", &http.Response{StatusCode: 404}, fmt.Errorf("not found"))
		ctx, err = addRawAPIErrorToContext(ctx, rawErr)
		require.NoError(t, err)

		// Then we should be able to retrieve all errors
		apiErrors, err := GetGitHubAPIErrors(ctx)
		require.NoError(t, err)
		assert.Len(t, apiErrors, 2)

		gqlErrors, err := GetGitHubGraphQLErrors(ctx)
		require.NoError(t, err)
		assert.Len(t, gqlErrors, 1)

		rawErrors, err := GetGitHubRawAPIErrors(ctx)
		require.NoError(t, err)
		assert.Len(t, rawErrors, 1)

		// Verify error details
		assert.Equal(t, "first error", apiErrors[0].Message)
		assert.Equal(t, "second error", apiErrors[1].Message)
		assert.Equal(t, "graphql error", gqlErrors[0].Message)
		assert.Equal(t, "raw error", rawErrors[0].Message)
	})

	t.Run("context pointer sharing allows middleware to inspect errors without context propagation", func(t *testing.T) {
		// This test demonstrates the key behavior: even when the context itself
		// isn't propagated through function calls, the pointer to the error slice
		// is shared, allowing middleware to inspect errors that were added later.

		// Given a context with GitHub error tracking enabled
		originalCtx := ContextWithGitHubErrors(context.Background())

		// Simulate a middleware that captures the context early
		var middlewareCtx context.Context

		// Middleware function that captures the context
		middleware := func(ctx context.Context) {
			middlewareCtx = ctx // Middleware saves the context reference
		}

		// Call middleware with the original context
		middleware(originalCtx)

		// Simulate some business logic that adds errors to the context
		// but doesn't propagate the updated context back to middleware
		businessLogic := func(ctx context.Context) {
			resp := &github.Response{Response: &http.Response{StatusCode: 500}}

			// Add an error to the context (this modifies the shared pointer)
			_, err := NewGitHubAPIErrorToCtx(ctx, "business logic failed", resp, fmt.Errorf("internal error"))
			require.NoError(t, err)

			// Add another error
			_, err = NewGitHubAPIErrorToCtx(ctx, "second failure", resp, fmt.Errorf("another error"))
			require.NoError(t, err)
		}

		// Execute business logic - note that we don't propagate the returned context
		businessLogic(originalCtx)

		// Then the middleware should be able to see the errors that were added
		// even though it only has a reference to the original context
		apiErrors, err := GetGitHubAPIErrors(middlewareCtx)
		require.NoError(t, err)
		assert.Len(t, apiErrors, 2, "Middleware should see errors added after it captured the context")

		assert.Equal(t, "business logic failed", apiErrors[0].Message)
		assert.Equal(t, "second failure", apiErrors[1].Message)
	})

	t.Run("context without GitHub errors returns error", func(t *testing.T) {
		// Given a regular context without GitHub error tracking
		ctx := context.Background()

		// When we try to retrieve errors
		apiErrors, err := GetGitHubAPIErrors(ctx)

		// Then it should return an error
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "context does not contain GitHubCtxErrors")
		assert.Nil(t, apiErrors)

		// Same for GraphQL errors
		gqlErrors, err := GetGitHubGraphQLErrors(ctx)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "context does not contain GitHubCtxErrors")
		assert.Nil(t, gqlErrors)

		// Same for raw API errors
		rawErrors, err := GetGitHubRawAPIErrors(ctx)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "context does not contain GitHubCtxErrors")
		assert.Nil(t, rawErrors)
	})

	t.Run("ContextWithGitHubErrors resets existing errors", func(t *testing.T) {
		// Given a context with existing errors
		ctx := ContextWithGitHubErrors(context.Background())
		resp := &github.Response{Response: &http.Response{StatusCode: 404}}
		ctx, err := NewGitHubAPIErrorToCtx(ctx, "existing error", resp, fmt.Errorf("error"))
		require.NoError(t, err)

		// Add a raw API error too
		rawErr := newGitHubRawAPIError("existing raw error", &http.Response{StatusCode: 404}, fmt.Errorf("error"))
		ctx, err = addRawAPIErrorToContext(ctx, rawErr)
		require.NoError(t, err)

		// Verify errors exist
		apiErrors, err := GetGitHubAPIErrors(ctx)
		require.NoError(t, err)
		assert.Len(t, apiErrors, 1)

		rawErrors, err := GetGitHubRawAPIErrors(ctx)
		require.NoError(t, err)
		assert.Len(t, rawErrors, 1)

		// When we call ContextWithGitHubErrors again
		resetCtx := ContextWithGitHubErrors(ctx)

		// Then all errors should be cleared
		apiErrors, err = GetGitHubAPIErrors(resetCtx)
		require.NoError(t, err)
		assert.Len(t, apiErrors, 0, "API errors should be reset")

		rawErrors, err = GetGitHubRawAPIErrors(resetCtx)
		require.NoError(t, err)
		assert.Len(t, rawErrors, 0, "Raw API errors should be reset")
	})

	t.Run("NewGitHubAPIErrorResponse creates MCP error result and stores context error", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		resp := &github.Response{Response: &http.Response{StatusCode: 422}}
		originalErr := fmt.Errorf("validation failed")

		// When we create an API error response
		result := NewGitHubAPIErrorResponse(ctx, "API call failed", resp, originalErr)

		// Then it should return an MCP error result
		require.NotNil(t, result)
		assert.True(t, result.IsError)

		// And the error should be stored in the context
		apiErrors, err := GetGitHubAPIErrors(ctx)
		require.NoError(t, err)
		require.Len(t, apiErrors, 1)

		apiError := apiErrors[0]
		assert.Equal(t, "API call failed", apiError.Message)
		assert.Equal(t, resp, apiError.Response)
		assert.Equal(t, originalErr, apiError.Err)
	})

	t.Run("NewGitHubGraphQLErrorResponse creates MCP error result and stores context error", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		originalErr := fmt.Errorf("mutation failed")

		// When we create a GraphQL error response
		result := NewGitHubGraphQLErrorResponse(ctx, "GraphQL call failed", originalErr)

		// Then it should return an MCP error result
		require.NotNil(t, result)
		assert.True(t, result.IsError)

		// And the error should be stored in the context
		gqlErrors, err := GetGitHubGraphQLErrors(ctx)
		require.NoError(t, err)
		require.Len(t, gqlErrors, 1)

		gqlError := gqlErrors[0]
		assert.Equal(t, "GraphQL call failed", gqlError.Message)
		assert.Equal(t, originalErr, gqlError.Err)
	})

	t.Run("NewGitHubAPIStatusErrorResponse creates MCP error result from status code", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		resp := &github.Response{Response: &http.Response{StatusCode: 422}}
		body := []byte(`{"message": "Validation Failed"}`)

		// When we create a status error response
		result := NewGitHubAPIStatusErrorResponse(ctx, "failed to create issue", resp, body)

		// Then it should return an MCP error result
		require.NotNil(t, result)
		assert.True(t, result.IsError)

		// And the error should be stored in the context
		apiErrors, err := GetGitHubAPIErrors(ctx)
		require.NoError(t, err)
		require.Len(t, apiErrors, 1)

		apiError := apiErrors[0]
		assert.Equal(t, "failed to create issue", apiError.Message)
		assert.Equal(t, resp, apiError.Response)
		// The synthetic error should contain the status code and body
		assert.Contains(t, apiError.Err.Error(), "unexpected status 422")
		assert.Contains(t, apiError.Err.Error(), "Validation Failed")
	})

	t.Run("NewGitHubAPIErrorToCtx with uninitialized context does not error", func(t *testing.T) {
		// Given a regular context without GitHub error tracking initialized
		ctx := context.Background()

		// Create a mock GitHub response
		resp := &github.Response{
			Response: &http.Response{
				StatusCode: 500,
				Status:     "500 Internal Server Error",
			},
		}
		originalErr := fmt.Errorf("internal server error")

		// When we try to add an API error to an uninitialized context
		updatedCtx, err := NewGitHubAPIErrorToCtx(ctx, "failed operation", resp, originalErr)

		// Then it should not return an error (graceful handling)
		assert.NoError(t, err, "NewGitHubAPIErrorToCtx should handle uninitialized context gracefully")
		assert.Equal(t, ctx, updatedCtx, "Context should be returned unchanged when not initialized")

		// And attempting to retrieve errors should still return an error since context wasn't initialized
		apiErrors, err := GetGitHubAPIErrors(updatedCtx)
		assert.Error(t, err)
		assert.Contains(t, err.Error(), "context does not contain GitHubCtxErrors")
		assert.Nil(t, apiErrors)
	})

	t.Run("NewGitHubAPIErrorToCtx with nil context does not error", func(t *testing.T) {
		// Given a nil context
		var ctx context.Context

		// Create a mock GitHub response
		resp := &github.Response{
			Response: &http.Response{
				StatusCode: 400,
				Status:     "400 Bad Request",
			},
		}
		originalErr := fmt.Errorf("bad request")

		// When we try to add an API error to a nil context
		updatedCtx, err := NewGitHubAPIErrorToCtx(ctx, "failed with nil context", resp, originalErr)

		// Then it should not return an error (graceful handling)
		assert.NoError(t, err, "NewGitHubAPIErrorToCtx should handle nil context gracefully")
		assert.Nil(t, updatedCtx, "Context should remain nil when passed as nil")
	})
}

func TestGitHubErrorTypes(t *testing.T) {
	t.Run("GitHubAPIError implements error interface", func(t *testing.T) {
		resp := &github.Response{Response: &http.Response{StatusCode: 404}}
		originalErr := fmt.Errorf("not found")

		apiErr := newGitHubAPIError("test message", resp, originalErr)

		// Should implement error interface
		var err error = apiErr
		assert.Equal(t, "test message: not found", err.Error())
	})

	t.Run("GitHubGraphQLError implements error interface", func(t *testing.T) {
		originalErr := fmt.Errorf("query failed")

		gqlErr := newGitHubGraphQLError("test message", originalErr)

		// Should implement error interface
		var err error = gqlErr
		assert.Equal(t, "test message: query failed", err.Error())
	})
}

// TestMiddlewareScenario demonstrates a realistic middleware scenario
func TestMiddlewareScenario(t *testing.T) {
	t.Run("realistic middleware error collection scenario", func(t *testing.T) {
		// Simulate a realistic HTTP middleware scenario

		// 1. Request comes in, middleware sets up error tracking
		ctx := ContextWithGitHubErrors(context.Background())

		// 2. Middleware stores reference to context for later inspection
		var middlewareCtx context.Context
		setupMiddleware := func(ctx context.Context) context.Context {
			middlewareCtx = ctx
			return ctx
		}

		// 3. Setup middleware
		ctx = setupMiddleware(ctx)

		// 4. Simulate multiple service calls that add errors
		simulateServiceCall1 := func(ctx context.Context) {
			resp := &github.Response{Response: &http.Response{StatusCode: 403}}
			_, err := NewGitHubAPIErrorToCtx(ctx, "insufficient permissions", resp, fmt.Errorf("forbidden"))
			require.NoError(t, err)
		}

		simulateServiceCall2 := func(ctx context.Context) {
			resp := &github.Response{Response: &http.Response{StatusCode: 404}}
			_, err := NewGitHubAPIErrorToCtx(ctx, "resource not found", resp, fmt.Errorf("not found"))
			require.NoError(t, err)
		}

		simulateGraphQLCall := func(ctx context.Context) {
			gqlErr := newGitHubGraphQLError("mutation failed", fmt.Errorf("invalid input"))
			_, err := addGitHubGraphQLErrorToContext(ctx, gqlErr)
			require.NoError(t, err)
		}

		// 5. Execute service calls (without context propagation)
		simulateServiceCall1(ctx)
		simulateServiceCall2(ctx)
		simulateGraphQLCall(ctx)

		// 6. Middleware inspects errors at the end of request processing
		finalizeMiddleware := func(ctx context.Context) ([]string, []string) {
			var apiErrorMessages []string
			var gqlErrorMessages []string

			if apiErrors, err := GetGitHubAPIErrors(ctx); err == nil {
				for _, apiErr := range apiErrors {
					apiErrorMessages = append(apiErrorMessages, apiErr.Message)
				}
			}

			if gqlErrors, err := GetGitHubGraphQLErrors(ctx); err == nil {
				for _, gqlErr := range gqlErrors {
					gqlErrorMessages = append(gqlErrorMessages, gqlErr.Message)
				}
			}

			return apiErrorMessages, gqlErrorMessages
		}

		// 7. Middleware can see all errors that were added during request processing
		apiMessages, gqlMessages := finalizeMiddleware(middlewareCtx)

		// Verify all errors were captured
		assert.Len(t, apiMessages, 2)
		assert.Contains(t, apiMessages, "insufficient permissions")
		assert.Contains(t, apiMessages, "resource not found")

		assert.Len(t, gqlMessages, 1)
		assert.Contains(t, gqlMessages, "mutation failed")
	})
}

// requireErrorText asserts that result is a non-nil MCP tool error and returns its text content.
func requireErrorText(t *testing.T, result *mcp.CallToolResult) string {
	t.Helper()
	require.NotNil(t, result)
	require.True(t, result.IsError)
	require.NotEmpty(t, result.Content)
	text, ok := result.Content[0].(*mcp.TextContent)
	require.True(t, ok, "expected *mcp.TextContent, got %T", result.Content[0])
	return text.Text
}

// assertContextHasError asserts that exactly one error is stored in ctx and it matches expectedErr.
//
//nolint:revive // t must be first for test helpers; context-as-argument doesn't apply here
func assertContextHasError(t *testing.T, ctx context.Context, expectedErr error) {
	t.Helper()
	apiErrors, err := GetGitHubAPIErrors(ctx)
	require.NoError(t, err)
	require.Len(t, apiErrors, 1)
	assert.Equal(t, expectedErr, apiErrors[0].Err)
}

func TestNewGitHubAPIErrorResponse_RateLimits(t *testing.T) {
	t.Run("RateLimitError produces clean message with retry time", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		resetTime := time.Now().Add(30 * time.Minute)
		rateLimitErr := &github.RateLimitError{
			Rate:     github.Rate{Reset: github.Timestamp{Time: resetTime}},
			Response: &http.Response{StatusCode: 403},
			Message:  "API rate limit exceeded",
		}
		resp := &github.Response{Response: rateLimitErr.Response}

		// Capture expected duration before the call so both use the same time.Until snapshot
		expectedRetryIn := time.Until(resetTime).Round(time.Second)

		// When we create an API error response for a rate limit error
		result := NewGitHubAPIErrorResponse(ctx, "search code", resp, rateLimitErr)

		// Then the message should be clean and actionable (no raw URLs or status codes)
		text := requireErrorText(t, result)
		assert.Contains(t, text, fmt.Sprintf("GitHub API rate limit exceeded. Retry after %v.", expectedRetryIn))
		assert.NotContains(t, text, "https://")
		assert.NotContains(t, text, "403")

		// And the original error should still be stored in context for middleware
		assertContextHasError(t, ctx, rateLimitErr)
	})

	t.Run("AbuseRateLimitError with RetryAfter produces clean message with wait time", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		retryAfter := 47 * time.Second
		abuseErr := &github.AbuseRateLimitError{
			Response:   &http.Response{StatusCode: 403},
			Message:    "You have exceeded a secondary rate limit.",
			RetryAfter: &retryAfter,
		}
		resp := &github.Response{Response: abuseErr.Response}

		// When we create an API error response for a secondary rate limit error
		result := NewGitHubAPIErrorResponse(ctx, "create issue", resp, abuseErr)

		// And the message should include the specific retry duration
		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub secondary rate limit exceeded. Retry after 47s.")
		assert.NotContains(t, text, "https://")
		assert.NotContains(t, text, "403")

		// And the original error should still be stored in context for middleware
		assertContextHasError(t, ctx, abuseErr)
	})

	t.Run("AbuseRateLimitError without RetryAfter produces clean message without wait time", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		abuseErr := &github.AbuseRateLimitError{
			Response:   &http.Response{StatusCode: 403},
			Message:    "You have exceeded a secondary rate limit.",
			RetryAfter: nil,
		}
		resp := &github.Response{Response: abuseErr.Response}

		// When we create an API error response for a secondary rate limit error without retry info
		result := NewGitHubAPIErrorResponse(ctx, "create issue", resp, abuseErr)

		// And the message should be clean and actionable
		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub secondary rate limit exceeded. Wait before retrying.")
		assert.NotContains(t, text, "https://")
		assert.NotContains(t, text, "403")

		// And the original error should still be stored in context for middleware
		assertContextHasError(t, ctx, abuseErr)
	})

	t.Run("AbuseRateLimitError with sub-second RetryAfter falls back to wait message", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		// 200ms rounds to 0s, so should fall back to the generic wait message
		retryAfter := 200 * time.Millisecond
		abuseErr := &github.AbuseRateLimitError{
			Response:   &http.Response{StatusCode: 403},
			Message:    "You have exceeded a secondary rate limit.",
			RetryAfter: &retryAfter,
		}
		resp := &github.Response{Response: abuseErr.Response}

		result := NewGitHubAPIErrorResponse(ctx, "create issue", resp, abuseErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub secondary rate limit exceeded. Wait before retrying.")
	})

	t.Run("RateLimitError with reset time in the past falls back to wait message", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		resetTime := time.Now().Add(-5 * time.Second) // already passed
		rateLimitErr := &github.RateLimitError{
			Rate:     github.Rate{Reset: github.Timestamp{Time: resetTime}},
			Response: &http.Response{StatusCode: 403},
			Message:  "API rate limit exceeded",
		}
		resp := &github.Response{Response: rateLimitErr.Response}

		result := NewGitHubAPIErrorResponse(ctx, "search code", resp, rateLimitErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub API rate limit exceeded. Wait before retrying.")
	})

	t.Run("RateLimitError with sub-second reset time falls back to wait message", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		// 250ms in the future: still positive, but rounds to 0s, so should fall back
		resetTime := time.Now().Add(250 * time.Millisecond)
		rateLimitErr := &github.RateLimitError{
			Rate:     github.Rate{Reset: github.Timestamp{Time: resetTime}},
			Response: &http.Response{StatusCode: 403},
			Message:  "API rate limit exceeded",
		}
		resp := &github.Response{Response: rateLimitErr.Response}

		result := NewGitHubAPIErrorResponse(ctx, "search code", resp, rateLimitErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub API rate limit exceeded. Wait before retrying.")
	})

	t.Run("RateLimitError with zero reset time falls back to wait message", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		rateLimitErr := &github.RateLimitError{
			Rate:     github.Rate{}, // zero Reset time
			Response: &http.Response{StatusCode: 403},
			Message:  "API rate limit exceeded",
		}
		resp := &github.Response{Response: rateLimitErr.Response}

		result := NewGitHubAPIErrorResponse(ctx, "search code", resp, rateLimitErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub API rate limit exceeded. Wait before retrying.")
	})

	t.Run("wrapped RateLimitError is handled via errors.As", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		resetTime := time.Now().Add(20 * time.Minute)
		rateLimitErr := &github.RateLimitError{
			Rate:     github.Rate{Reset: github.Timestamp{Time: resetTime}},
			Response: &http.Response{StatusCode: 403},
			Message:  "API rate limit exceeded",
		}
		wrappedErr := fmt.Errorf("transport layer: %w", rateLimitErr)
		resp := &github.Response{Response: rateLimitErr.Response}

		// Capture expected duration before the call so both use the same time.Until snapshot
		expectedRetryIn := time.Until(resetTime).Round(time.Second)

		result := NewGitHubAPIErrorResponse(ctx, "search code", resp, wrappedErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, fmt.Sprintf("GitHub API rate limit exceeded. Retry after %v.", expectedRetryIn))
		assert.NotContains(t, text, "https://")
	})

	t.Run("wrapped AbuseRateLimitError is handled via errors.As", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		retryAfter := 30 * time.Second
		abuseErr := &github.AbuseRateLimitError{
			Response:   &http.Response{StatusCode: 403},
			Message:    "secondary rate limit",
			RetryAfter: &retryAfter,
		}
		wrappedErr := fmt.Errorf("transport layer: %w", abuseErr)
		resp := &github.Response{Response: abuseErr.Response}

		result := NewGitHubAPIErrorResponse(ctx, "create issue", resp, wrappedErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "GitHub secondary rate limit exceeded. Retry after 30s.")
		assert.NotContains(t, text, "https://")
	})

	t.Run("non-rate-limit GitHub API error passes through the original error message", func(t *testing.T) {
		// Given a context with GitHub error tracking enabled
		ctx := ContextWithGitHubErrors(context.Background())

		resp := &github.Response{Response: &http.Response{StatusCode: 422}}
		originalErr := fmt.Errorf("validation failed")

		// When we create an API error response for a non-rate-limit error
		result := NewGitHubAPIErrorResponse(ctx, "API call failed", resp, originalErr)

		// Then the message should contain the original error text unchanged
		text := requireErrorText(t, result)
		assert.Contains(t, text, "validation failed")
	})
}

func TestNewGitHubAPIErrorResponse_ValidationMessages(t *testing.T) {
	t.Run("ruleset ErrorResponse includes nested validation messages", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		originalErr := &github.ErrorResponse{
			Response: &http.Response{StatusCode: http.StatusUnprocessableEntity},
			Message:  "Validation Failed",
			Errors: []github.Error{
				{
					Resource: "GitRef",
					Field:    "ref",
					Code:     "custom",
					Message:  "ref name does not match the required pattern 'feature/*'",
				},
			},
			DocumentationURL: "https://docs.github.com/rest/git/refs#create-a-reference",
		}

		result := NewGitHubAPIErrorResponse(ctx, "failed to create branch", nil, originalErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "failed to create branch")
		assert.Contains(t, text, "HTTP 422 Validation Failed")
		assert.Contains(t, text, "ref name does not match the required pattern 'feature/*'")
		assert.Contains(t, text, "See https://docs.github.com/rest/git/refs#create-a-reference")
		assert.NotContains(t, text, "Resource:")
	})

	t.Run("wrapped ErrorResponse is still unwrapped", func(t *testing.T) {
		ctx := ContextWithGitHubErrors(context.Background())

		originalErr := fmt.Errorf("create ref: %w", &github.ErrorResponse{
			Response: &http.Response{StatusCode: http.StatusUnprocessableEntity},
			Message:  "Validation Failed",
			Errors: []github.Error{
				{Message: "Changes must be made through a pull request."},
			},
		})

		result := NewGitHubAPIErrorResponse(ctx, "failed to create branch", nil, originalErr)

		text := requireErrorText(t, result)
		assert.Contains(t, text, "Changes must be made through a pull request.")
		assert.NotContains(t, text, "create ref:")
	})
}