Add decompression middleware and tests for gzip handling

.gitignore

@@ -29,3 +29,4 @@ member-console
 
 # Ignore config files
 site/member-console.yaml
+**/.claude/settings.local.json

internal/middleware/decompress.go

@@ -0,0 +1,77 @@
+package middleware
+
+import (
+	"compress/gzip"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// DecompressOptions configures the decompression middleware
+type DecompressOptions struct {
+	// MaxSize is the maximum size of the decompressed body in bytes
+	// Zero means no limit
+	MaxSize int64
+}
+
+// DefaultDecompressOptions provides sensible default options
+func DefaultDecompressOptions() *DecompressOptions {
+	return &DecompressOptions{
+		MaxSize: 10 << 20, // 10MB
+	}
+}
+
+// Decompress creates a middleware that decompresses HTTP requests with gzip content encoding
+func Decompress(opts *DecompressOptions) Middleware {
+	// Use default options if none provided
+	if opts == nil {
+		opts = DefaultDecompressOptions()
+	}
+
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			// Check if the request has Content-Encoding header
+			contentEncoding := r.Header.Get("Content-Encoding")
+			
+			// If not compressed, pass through
+			if contentEncoding == "" {
+				next.ServeHTTP(w, r)
+				return
+			}
+			
+			// Check if gzip encoded
+			if strings.Contains(contentEncoding, "gzip") {
+				// Create a gzip reader
+				gz, err := gzip.NewReader(r.Body)
+				if err != nil {
+					http.Error(w, "Invalid gzip body", http.StatusBadRequest)
+					return
+				}
+				defer gz.Close()
+				
+				// Add limit reader if max size is specified
+				var bodyReader io.Reader = gz
+				if opts.MaxSize > 0 {
+					bodyReader = io.LimitReader(gz, opts.MaxSize)
+				}
+				
+				// Replace the body with a decompressed reader
+				r.Body = io.NopCloser(bodyReader)
+				
+				// Remove the content-encoding header to signal that the body is now decompressed
+				r.Header.Del("Content-Encoding")
+				
+				// Adjust content length because the body has been decompressed
+				r.Header.Del("Content-Length")
+			}
+			
+			// Call the next handler with the decompressed body
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// DecompressDefault creates a middleware that decompresses HTTP requests with default options
+func DecompressDefault() Middleware {
+	return Decompress(nil)
+}

internal/middleware/tests/decompress_test.go

@@ -0,0 +1,124 @@
+package tests
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"git.coopcloud.tech/wiki-cafe/member-console/internal/middleware"
+)
+
+func TestDecompressMiddleware(t *testing.T) {
+	// Create a simple handler that reads the request body and returns it
+	testHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			http.Error(w, "Error reading body", http.StatusInternalServerError)
+			return
+		}
+		w.Write(body)
+	})
+
+	// Apply decompression middleware
+	handler := middleware.DecompressDefault()(testHandler)
+
+	t.Run("No compression", func(t *testing.T) {
+		// Create a request with no compression
+		testData := []byte("test data with no compression")
+		req := httptest.NewRequest("POST", "/", bytes.NewReader(testData))
+		rr := httptest.NewRecorder()
+
+		// Call the handler
+		handler.ServeHTTP(rr, req)
+
+		// Check the response
+		if rr.Code != http.StatusOK {
+			t.Errorf("Expected status code %d, got %d", http.StatusOK, rr.Code)
+		}
+		if !bytes.Equal(testData, rr.Body.Bytes()) {
+			t.Errorf("Response body does not match original data")
+		}
+	})
+
+	t.Run("Gzip compression", func(t *testing.T) {
+		// Create gzip compressed data
+		testData := []byte("test data with gzip compression")
+		var buf bytes.Buffer
+		gzWriter := gzip.NewWriter(&buf)
+		_, err := gzWriter.Write(testData)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := gzWriter.Close(); err != nil {
+			t.Fatal(err)
+		}
+
+		// Create a request with gzip compression
+		req := httptest.NewRequest("POST", "/", &buf)
+		req.Header.Set("Content-Encoding", "gzip")
+		rr := httptest.NewRecorder()
+
+		// Call the handler
+		handler.ServeHTTP(rr, req)
+
+		// Check the response
+		if rr.Code != http.StatusOK {
+			t.Errorf("Expected status code %d, got %d", http.StatusOK, rr.Code)
+		}
+		if !bytes.Equal(testData, rr.Body.Bytes()) {
+			t.Errorf("Response body does not match original data")
+		}
+	})
+
+	t.Run("Invalid gzip data", func(t *testing.T) {
+		// Create invalid gzip data
+		testData := []byte("this is not valid gzip data")
+		req := httptest.NewRequest("POST", "/", bytes.NewReader(testData))
+		req.Header.Set("Content-Encoding", "gzip")
+		rr := httptest.NewRecorder()
+
+		// Call the handler
+		handler.ServeHTTP(rr, req)
+
+		// Check that we get a bad request
+		if rr.Code != http.StatusBadRequest {
+			t.Errorf("Expected status code %d, got %d", http.StatusBadRequest, rr.Code)
+		}
+	})
+
+	t.Run("Size limit", func(t *testing.T) {
+		// Create oversized data
+		testData := bytes.Repeat([]byte("a"), 11<<20) // 11MB
+		var buf bytes.Buffer
+		gzWriter := gzip.NewWriter(&buf)
+		_, err := gzWriter.Write(testData)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if err := gzWriter.Close(); err != nil {
+			t.Fatal(err)
+		}
+
+		// Create a limited decompression middleware (10MB limit)
+		limitedHandler := middleware.Decompress(nil)(testHandler)
+
+		// Create a request with gzip compression
+		req := httptest.NewRequest("POST", "/", &buf)
+		req.Header.Set("Content-Encoding", "gzip")
+		rr := httptest.NewRecorder()
+
+		// Call the handler
+		limitedHandler.ServeHTTP(rr, req)
+
+		// The request should process but the body will be truncated
+		if rr.Code != http.StatusOK {
+			t.Errorf("Expected status code %d, got %d", http.StatusOK, rr.Code)
+		}
+		if len(rr.Body.Bytes()) >= 11<<20 {
+			t.Errorf("Expected response to be truncated to less than 11MB, got %d bytes", len(rr.Body.Bytes()))
+		}
+	})
+}