feat: improve HTTP integration with JSON, Map, and Headers helpers

Author: SemmiDev

http.go

@@ -5,10 +5,13 @@ import (
 	"net/http"
 )
 
+// ContentType is the standard media type for Problem Details over HTTP.
+const ContentType = "application/problem+json; charset=utf-8"
+
 // Write automatically writes the Problem Details as a JSON HTTP response
 // with the correct Application/Problem+JSON content type.
 func (p *Problem) Write(w http.ResponseWriter) error {
-	w.Header().Set("Content-Type", "application/problem+json; charset=utf-8")
+	w.Header().Set("Content-Type", ContentType)
 	w.Header().Set("X-Content-Type-Options", "nosniff")
 	w.WriteHeader(p.Status)
 
@@ -22,6 +25,31 @@ func (p *Problem) Write(w http.ResponseWriter) error {
 	return nil
 }
 
-// Handler is a generic middleware interface or handler concept, but realistically
-// you just need `problem.Write(w)`.
-// We can provide a functional wrapper if you wanted, but usually `Write` is enough.
+// JSON returns the JSON encoding of the Problem.
+// This is useful for frameworks like Gin, Echo, or Fiber where you might
+// want to write the raw JSON bytes directly and set the Content-Type manually.
+func (p *Problem) JSON() []byte {
+	b, _ := json.Marshal(p)
+	return b
+}
+
+// Headers returns a map of HTTP headers that should be set when returning this problem.
+// This is convenient for translating to other framework's header structures.
+func (p *Problem) Headers() map[string]string {
+	return map[string]string{
+		"Content-Type":           ContentType,
+		"X-Content-Type-Options": "nosniff",
+	}
+}
+
+// Map converts the Problem to a generic map map[string]any.
+// This is particularly useful when returning Problem Details via frameworks
+// that prefer or require maps for custom JSON serialization overrides.
+func (p *Problem) Map() map[string]any {
+	var m map[string]any
+	// Reusing Marshal/Unmarshal avoids duplicating MarshalJSON logic
+	// and preserves consistency with the struct's existing serialization.
+	b, _ := json.Marshal(p)
+	_ = json.Unmarshal(b, &m)
+	return m
+}

problem_test.go

@@ -163,3 +163,41 @@ func TestProblemHTTPWrite(t *testing.T) {
 		t.Errorf("expected nosniff, got %v", snif)
 	}
 }
+
+func TestProblemHTTPHelpers(t *testing.T) {
+	p := problem.New(problem.BadRequest, problem.WithDetail("Invalid ID"))
+
+	t.Run("Headers", func(t *testing.T) {
+		headers := p.Headers()
+		if headers["Content-Type"] != problem.ContentType {
+			t.Errorf("expected Content-Type %s, got %s", problem.ContentType, headers["Content-Type"])
+		}
+		if headers["X-Content-Type-Options"] != "nosniff" {
+			t.Errorf("expected X-Content-Type-Options nosniff, got %s", headers["X-Content-Type-Options"])
+		}
+	})
+
+	t.Run("JSON", func(t *testing.T) {
+		data := p.JSON()
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("JSON() returned invalid json: %v", err)
+		}
+		if m["title"] != "Bad Request" || m["detail"] != "Invalid ID" {
+			t.Errorf("JSON() content mismatch: %v", m)
+		}
+	})
+
+	t.Run("Map", func(t *testing.T) {
+		m := p.Map()
+		if m["title"] != "Bad Request" {
+			t.Errorf("Map() expected title 'Bad Request', got %v", m["title"])
+		}
+		if m["status"].(float64) != 400 {
+			t.Errorf("Map() expected status 400, got %v", m["status"])
+		}
+		if m["detail"] != "Invalid ID" {
+			t.Errorf("Map() expected detail 'Invalid ID', got %v", m["detail"])
+		}
+	})
+}