feat(capability/mcp): MCP 客户端（stdlib JSON-RPC over stdio/SSE）+ Registry 自动注册/Unregister（registry 增 Remove）

internal/capability/mcp/helpers_test.go

@@ -0,0 +1,99 @@
+package mcp
+
+import (
+	"context"
+	"sync"
+)
+
+// fakeTransport is a scripted Transport for tests. It records starts, closes and
+// the methods it was asked to call so assertions can verify the client's usage.
+type fakeTransport struct {
+	startErr error
+	closeErr error
+	initErr  error
+	listErr  error
+	callErr  error
+	tools    []ToolInfo
+
+	mu      sync.Mutex
+	starts  int
+	closes  int
+	methods []string
+}
+
+// Start records a start.
+func (f *fakeTransport) Start(_ context.Context) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.starts++
+	return f.startErr
+}
+
+// Call answers the three MCP methods the client issues.
+func (f *fakeTransport) Call(_ context.Context, method string, _ any, result any) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.methods = append(f.methods, method)
+	switch method {
+	case "initialize":
+		if f.initErr != nil {
+			return f.initErr
+		}
+		if r, ok := result.(*initializeResult); ok {
+			r.ServerInfo = serverInfo{Name: "fake-server", Version: "1.0"}
+			r.ProtocolVersion = protocolVersion
+		}
+	case "tools/list":
+		if f.listErr != nil {
+			return f.listErr
+		}
+		if r, ok := result.(*listToolsResult); ok {
+			for _, t := range f.tools {
+				r.Tools = append(r.Tools, toolSpec{Name: t.Name, Description: t.Description, InputSchema: t.InputSchema})
+			}
+		}
+	case "tools/call":
+		if f.callErr != nil {
+			return f.callErr
+		}
+		if r, ok := result.(*callToolResult); ok {
+			r.Content = []contentBlock{{Type: "text", Text: "hello"}}
+		}
+	}
+	return nil
+}
+
+// notify records a notification method.
+func (f *fakeTransport) notify(_ context.Context, method string, _ any) error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.methods = append(f.methods, "notify:"+method)
+	return nil
+}
+
+// Close records a close.
+func (f *fakeTransport) Close() error {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	f.closes++
+	return f.closeErr
+}
+
+// calledMethods returns a snapshot of the recorded methods.
+func (f *fakeTransport) calledMethods() []string {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	out := make([]string, len(f.methods))
+	copy(out, f.methods)
+	return out
+}
+
+// hasMethod reports whether method was recorded.
+func (f *fakeTransport) hasMethod(method string) bool {
+	for _, m := range f.calledMethods() {
+		if m == method {
+			return true
+		}
+	}
+	return false
+}