Unit Test Cases addition

go.mod

@@ -7,18 +7,24 @@ toolchain go1.24.13
 require (
 	github.com/modelcontextprotocol/go-sdk v1.2.0
 	github.com/prometheus/client_golang v1.22.0
+	github.com/stretchr/testify v1.11.1
 )
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/jsonschema-go v0.3.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.62.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	golang.org/x/oauth2 v0.30.0 // indirect
 	golang.org/x/sys v0.30.0 // indirect
 	google.golang.org/protobuf v1.36.5 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -2,6 +2,7 @@ github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/golang-jwt/jwt/v5 v5.2.2 h1:Rl4B7itRWVtYIHFrSNd7vhTiz9UpLdi6gZhZ3wEeDy8=
@@ -10,6 +11,12 @@ github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 github.com/google/jsonschema-go v0.3.0 h1:6AH2TxVNtk3IlvkkhjrtbUc4S8AvO0Xii0DxIygDg+Q=
 github.com/google/jsonschema-go v0.3.0/go.mod h1:r5quNTdLOYEz95Ru18zA0ydNbBuYoo9tgaYcxEYhJVE=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
+github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
 github.com/modelcontextprotocol/go-sdk v1.2.0 h1:Y23co09300CEk8iZ/tMxIX1dVmKZkzoSBZOpJwUnc/s=
 github.com/modelcontextprotocol/go-sdk v1.2.0/go.mod h1:6fM3LCm3yV7pAs8isnKLn07oKtB0MP9LHd3DfAcKw10=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
@@ -24,8 +31,10 @@ github.com/prometheus/common v0.62.0 h1:xasJaQlnWAeyHdUBeGjXmutelfJHWMRr+Fg4QszZ
 github.com/prometheus/common v0.62.0/go.mod h1:vyBcEuLSvWos9B1+CyL7JZ2up+uFzXhkqml0W5zIY1I=
 github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0learggepc=
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
-github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
-github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
+github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
 github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
 golang.org/x/oauth2 v0.30.0 h1:dnDm7JmhM45NNpd8FDDeLhK6FwqbOf4MLCM9zb1BOHI=
@@ -36,5 +45,8 @@ golang.org/x/tools v0.34.0 h1:qIpSLOxeCYGg9TrcJokLBG4KFA6d795g0xkBkiESGlo=
 golang.org/x/tools v0.34.0/go.mod h1:pAP9OwEaY1CAW3HOmg3hLZC5Z0CCmzjAF2UQMSqNARg=
 google.golang.org/protobuf v1.36.5 h1:tPhr+woSbjfYvY6/GPufUoYizxw1cF/yFoxJ2fmpwlM=
 google.golang.org/protobuf v1.36.5/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

pkg/metrics/metrics_test.go

@@ -0,0 +1,61 @@
+package metrics_test
+
+import (
+	"testing"
+
+	"github.com/codeready-toolchain/mcp-common/pkg/metrics"
+
+	"github.com/prometheus/client_golang/prometheus/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMCPCallsTotal(t *testing.T) {
+	t.Run("counter is registered and can be incremented", func(t *testing.T) {
+		// given
+		require.NotNil(t, metrics.MCPCallsTotal)
+		counter := metrics.MCPCallsTotal.WithLabelValues("test-server", "tools/call", "my-tool", "true")
+		before := testutil.ToFloat64(counter)
+
+		// when
+		counter.Inc()
+
+		// then
+		after := testutil.ToFloat64(counter)
+		assert.InDelta(t, float64(1), after-before, 0)
+	})
+
+	t.Run("counter tracks different label combinations independently", func(t *testing.T) {
+		// given
+		require.NotNil(t, metrics.MCPCallsTotal)
+		successCounter := metrics.MCPCallsTotal.WithLabelValues("test-server", "tools/call", "tool-a", "true")
+		failureCounter := metrics.MCPCallsTotal.WithLabelValues("test-server", "tools/call", "tool-a", "false")
+
+		beforeSuccess := testutil.ToFloat64(successCounter)
+		beforeFailure := testutil.ToFloat64(failureCounter)
+
+		// when
+		successCounter.Inc()
+		successCounter.Inc()
+		failureCounter.Inc()
+
+		// then
+		assert.InDelta(t, float64(2), testutil.ToFloat64(successCounter)-beforeSuccess, 0)
+		assert.InDelta(t, float64(1), testutil.ToFloat64(failureCounter)-beforeFailure, 0)
+	})
+}
+
+func TestMCPCallDuration(t *testing.T) {
+	t.Run("histogram is registered and can observe values", func(t *testing.T) {
+		// given
+		require.NotNil(t, metrics.MCPCallDuration)
+		histogram := metrics.MCPCallDuration.WithLabelValues("test-server", "tools/call", "my-tool", "true")
+
+		// when
+		histogram.Observe(0.5)
+		histogram.Observe(1.0)
+
+		// then (no panic means histogram is working)
+		assert.NotNil(t, histogram)
+	})
+}

pkg/middleware/logging_test.go

@@ -0,0 +1,173 @@
+package middleware_test
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"log/slog"
+	"testing"
+
+	"github.com/codeready-toolchain/mcp-common/pkg/middleware"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewLoggingMiddleware(t *testing.T) {
+	t.Run("logs CallToolRequest with tool name on success", func(t *testing.T) {
+		// given
+		var buf bytes.Buffer
+		logger := slog.New(slog.NewJSONHandler(&buf, &slog.HandlerOptions{Level: slog.LevelDebug}))
+
+		nextCalled := false
+		expectedResult := &mcp.CallToolResult{
+			Content: []mcp.Content{&mcp.TextContent{Text: "result"}},
+		}
+		next := func(_ context.Context, _ string, _ mcp.Request) (mcp.Result, error) {
+			nextCalled = true
+			return expectedResult, nil
+		}
+
+		req := &mcp.ServerRequest[*mcp.CallToolParamsRaw]{
+			Session: &mcp.ServerSession{},
+			Params: &mcp.CallToolParamsRaw{
+				Name:      "my-tool",
+				Arguments: json.RawMessage(`{"key":"value"}`),
+			},
+		}
+
+		mw := middleware.NewLoggingMiddleware(logger)
+		handler := mw(next)
+
+		// when
+		result, err := handler(context.Background(), "tools/call", req)
+
+		// then
+		require.NoError(t, err)
+		assert.True(t, nextCalled)
+		assert.Equal(t, expectedResult, result)
+
+		logs := buf.String()
+		assert.Contains(t, logs, "MCP method started")
+		assert.Contains(t, logs, "my-tool")
+		assert.Contains(t, logs, "MCP call completed")
+		assert.Contains(t, logs, "tools/call")
+		assert.NotContains(t, logs, "MCP call failed")
+	})
+
+	t.Run("logs CallToolRequest without arguments", func(t *testing.T) {
+		// given
+		var buf bytes.Buffer
+		logger := slog.New(slog.NewJSONHandler(&buf, &slog.HandlerOptions{Level: slog.LevelDebug}))
+
+		next := func(_ context.Context, _ string, _ mcp.Request) (mcp.Result, error) {
+			return &mcp.CallToolResult{}, nil
+		}
+
+		req := &mcp.ServerRequest[*mcp.CallToolParamsRaw]{
+			Session: &mcp.ServerSession{},
+			Params:  &mcp.CallToolParamsRaw{Name: "no-args-tool"},
+		}
+
+		handler := middleware.NewLoggingMiddleware(logger)(next)
+
+		// when
+		_, err := handler(context.Background(), "tools/call", req)
+
+		// then
+		require.NoError(t, err)
+
+		logs := buf.String()
+		assert.Contains(t, logs, "no-args-tool")
+		assert.Contains(t, logs, `"has_args":false`)
+	})
+
+	t.Run("logs error when next handler returns error", func(t *testing.T) {
+		// given
+		var buf bytes.Buffer
+		logger := slog.New(slog.NewJSONHandler(&buf, &slog.HandlerOptions{Level: slog.LevelDebug}))
+
+		expectedErr := errors.New("something went wrong")
+		next := func(_ context.Context, _ string, _ mcp.Request) (mcp.Result, error) {
+			return nil, expectedErr
+		}
+
+		req := &mcp.ServerRequest[*mcp.CallToolParamsRaw]{
+			Session: &mcp.ServerSession{},
+			Params:  &mcp.CallToolParamsRaw{Name: "failing-tool"},
+		}
+
+		handler := middleware.NewLoggingMiddleware(logger)(next)
+
+		// when
+		result, err := handler(context.Background(), "tools/call", req)
+
+		// then
+		assert.Nil(t, result)
+		require.ErrorIs(t, err, expectedErr)
+
+		logs := buf.String()
+		assert.Contains(t, logs, "MCP call failed")
+		assert.Contains(t, logs, "something went wrong")
+		assert.NotContains(t, logs, "MCP call completed")
+	})
+
+	t.Run("logs non-CallToolRequest with has_params", func(t *testing.T) {
+		// given
+		var buf bytes.Buffer
+		logger := slog.New(slog.NewJSONHandler(&buf, &slog.HandlerOptions{Level: slog.LevelDebug}))
+
+		next := func(_ context.Context, _ string, _ mcp.Request) (mcp.Result, error) {
+			return nil, nil
+		}
+
+		req := &mcp.ServerRequest[*mcp.ListToolsParams]{
+			Session: &mcp.ServerSession{},
+			Params:  &mcp.ListToolsParams{},
+		}
+
+		handler := middleware.NewLoggingMiddleware(logger)(next)
+
+		// when
+		_, err := handler(context.Background(), "tools/list", req)
+
+		// then
+		require.NoError(t, err)
+
+		logs := buf.String()
+		assert.Contains(t, logs, "MCP method started")
+		assert.Contains(t, logs, "tools/list")
+		assert.Contains(t, logs, "has_params")
+		assert.NotContains(t, logs, "MCP call failed")
+	})
+
+	t.Run("next handler result is passed through", func(t *testing.T) {
+		// given
+		var buf bytes.Buffer
+		logger := slog.New(slog.NewJSONHandler(&buf, nil))
+
+		expectedResult := &mcp.CallToolResult{
+			Content: []mcp.Content{&mcp.TextContent{Text: "hello"}},
+			IsError: false,
+		}
+		next := func(_ context.Context, _ string, _ mcp.Request) (mcp.Result, error) {
+			return expectedResult, nil
+		}
+
+		req := &mcp.ServerRequest[*mcp.CallToolParamsRaw]{
+			Session: &mcp.ServerSession{},
+			Params:  &mcp.CallToolParamsRaw{Name: "pass-through-tool"},
+		}
+
+		handler := middleware.NewLoggingMiddleware(logger)(next)
+
+		// when
+		result, err := handler(context.Background(), "tools/call", req)
+
+		// then
+		require.NoError(t, err)
+		assert.Equal(t, expectedResult, result)
+	})
+}