Complete JSONC parsing fix for MCPConfig.UnmarshalJSON method

internal/mcp/config.go

@@ -66,12 +66,12 @@ func (c *MCPConfig) UnmarshalJSON(data []byte) error {
 	}{
 		Alias: (*Alias)(c),
 	}
-	if err := json.Unmarshal(data, &aux); err != nil {
+	if err := jsonc.Unmarshal(data, &aux); err != nil {
 		return err
 	}
 	// Unmarshal into a map to find extra fields
 	var all map[string]json.RawMessage
-	if err := json.Unmarshal(data, &all); err != nil {
+	if err := jsonc.Unmarshal(data, &all); err != nil {
 		return err
 	}
 	// Remove known fields
@@ -82,7 +82,7 @@ func (c *MCPConfig) UnmarshalJSON(data []byte) error {
 	c.Extra = make(map[string]interface{})
 	for k, v := range all {
 		var val interface{}
-		if err := json.Unmarshal(v, &val); err != nil {
+		if err := jsonc.Unmarshal(v, &val); err != nil {
 			c.Extra[k] = string(v) // fallback to raw string
 		} else {
 			c.Extra[k] = val
@@ -105,7 +105,7 @@ func (c *MCPConfig) MarshalJSON() ([]byte, error) {
 	}
 	// Unmarshal back into a map to merge with Extra
 	var m map[string]interface{}
-	if err := json.Unmarshal(data, &m); err != nil {
+	if err := jsonc.Unmarshal(data, &m); err != nil {
 		return nil, err
 	}
 	for k, v := range c.Extra {

internal/mcp/config_jsonc_test.go

@@ -0,0 +1,252 @@
+package mcp
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestJSONCCommentSupport(t *testing.T) {
+	tests := []struct {
+		name        string
+		jsonContent string
+		expectError bool
+	}{
+		{
+			name: "User's exact case: /* test */ at top",
+			jsonContent: `/* test */
+{
+  "editor.fontSize": 14,
+  "workbench.colorTheme": "Default Dark+",
+  "mcpServers": {
+    "agentuity": {
+      "command": "npx",
+      "args": ["-y", "@agentuity/mcp-server"],
+      "env": {
+        "AGENTUITY_API_KEY": "${AGENTUITY_API_KEY}"
+      }
+    }
+  }
+}`,
+			expectError: false,
+		},
+		{
+			name: "Single line comments",
+			jsonContent: `{
+  "editor.fontSize": 14,
+  "mcpServers": {
+    "agentuity": {
+      "command": "npx", // inline comment
+      "args": ["-y", "@agentuity/mcp-server"]
+    }
+  }
+}`,
+			expectError: false,
+		},
+		{
+			name: "Multi-line comments",
+			jsonContent: `{
+  /* This is a 
+     multi-line comment */
+  "mcpServers": {
+    "test": {
+      "command": "test"
+    }
+  },
+  /* Another comment */
+  "ampMcpServers": {
+    "amp": {
+      "command": "amp"
+    }
+  }
+}`,
+			expectError: false,
+		},
+		{
+			name: "Mixed comments comprehensive",
+			jsonContent: `{
+  /* test comment at start */
+  "editor.fontSize": 14,
+  "workbench.colorTheme": "Default Dark+",
+  "mcpServers": {
+    "agentuity": {
+      "command": "npx", // inline comment
+      "args": ["-y", "@agentuity/mcp-server"],
+      "env": {
+        "AGENTUITY_API_KEY": "${AGENTUITY_API_KEY}" /* env var comment */
+      }
+    }
+  },
+  /* Extension settings */
+  "extensions.autoUpdate": false,
+  "ampMcpServers": {
+    "test": {
+      "command": "test"
+    }
+  }
+}`,
+			expectError: false,
+		},
+		{
+			name: "Empty JSON with comment",
+			jsonContent: `/* test */
+{
+}`,
+			expectError: false,
+		},
+		{
+			name: "Comment at end",
+			jsonContent: `{
+  "mcpServers": {
+    "test": {
+      "command": "test"
+    }
+  }
+}
+/* end comment */`,
+			expectError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpDir := t.TempDir()
+			configPath := filepath.Join(tmpDir, "test_config.json")
+
+			err := os.WriteFile(configPath, []byte(tt.jsonContent), 0644)
+			if err != nil {
+				t.Fatalf("Failed to write test file: %v", err)
+			}
+
+			config, err := loadConfig(configPath)
+			if tt.expectError {
+				if err == nil {
+					t.Errorf("Expected error but got none")
+				}
+				return
+			}
+
+			if err != nil {
+				t.Errorf("Unexpected error: %v", err)
+				return
+			}
+
+			if config == nil {
+				t.Errorf("Config should not be nil")
+				return
+			}
+
+			t.Logf("Successfully parsed config with %d mcpServers, %d ampMcpServers, %d extra fields",
+				len(config.MCPServers), len(config.AMPMCPServers), len(config.Extra))
+		})
+	}
+}
+
+func TestCompleteLoadSaveCycleWithComments(t *testing.T) {
+	jsonWithComments := `/* test comment */
+{
+  "editor.fontSize": 14,
+  "workbench.colorTheme": "Default Dark+",
+  "mcpServers": {
+    "agentuity": {
+      "command": "npx",
+      "args": ["-y", "@agentuity/mcp-server"],
+      "env": {
+        "AGENTUITY_API_KEY": "${AGENTUITY_API_KEY}"
+      }
+    }
+  },
+  /* Extension settings */
+  "extensions.autoUpdate": false
+}`
+
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "test_config.json")
+
+	err := os.WriteFile(configPath, []byte(jsonWithComments), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	config, err := loadConfig(configPath)
+	if err != nil {
+		t.Fatalf("Failed to load config: %v", err)
+	}
+
+	if len(config.MCPServers) != 1 {
+		t.Errorf("Expected 1 mcpServer, got %d", len(config.MCPServers))
+	}
+
+	if len(config.Extra) != 3 {
+		t.Errorf("Expected 3 extra fields, got %d", len(config.Extra))
+	}
+
+	marshaledData, err := config.MarshalJSON()
+	if err != nil {
+		t.Fatalf("Failed to marshal config: %v", err)
+	}
+
+	if len(marshaledData) == 0 {
+		t.Errorf("Marshaled data should not be empty")
+	}
+
+	t.Logf("Successfully completed load-save cycle with comments")
+}
+
+func TestCursorSettingsWithComments(t *testing.T) {
+	cursorSettings := `/* test */
+{
+  "editor.fontSize": 14,
+  "workbench.colorTheme": "Default Dark+",
+  "mcpServers": {
+    "agentuity": {
+      "command": "npx",
+      "args": ["-y", "@agentuity/mcp-server"],
+      "env": {
+        "AGENTUITY_API_KEY": "${AGENTUITY_API_KEY}"
+      }
+    },
+    "filesystem": {
+      "command": "npx",
+      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path/to/allowed/files"]
+    }
+  },
+  "extensions.autoUpdate": false
+}`
+
+	tmpDir := t.TempDir()
+	settingsPath := filepath.Join(tmpDir, "settings.json")
+
+	err := os.WriteFile(settingsPath, []byte(cursorSettings), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write Cursor settings file: %v", err)
+	}
+
+	config, err := loadConfig(settingsPath)
+	if err != nil {
+		t.Fatalf("Failed to load Cursor settings with comments: %v", err)
+	}
+
+	if len(config.MCPServers) != 2 {
+		t.Errorf("Expected 2 mcpServers in Cursor settings, got %d", len(config.MCPServers))
+	}
+
+	if _, exists := config.MCPServers["agentuity"]; !exists {
+		t.Errorf("Expected 'agentuity' mcpServer in Cursor settings")
+	}
+
+	if _, exists := config.MCPServers["filesystem"]; !exists {
+		t.Errorf("Expected 'filesystem' mcpServer in Cursor settings")
+	}
+
+	marshaledData, err := config.MarshalJSON()
+	if err != nil {
+		t.Fatalf("Failed to marshal Cursor settings: %v", err)
+	}
+
+	if len(marshaledData) == 0 {
+		t.Errorf("Marshaled Cursor settings should not be empty")
+	}
+
+	t.Logf("Successfully processed Cursor settings with /* test */ comment")
+}