Test coverage

.github/workflows/test.yml

@@ -0,0 +1,26 @@
+on: [push, pull_request]
+name: Test
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: "go.mod"
+
+      - name: Download dependencies
+        run: go mod download
+
+      - name: Install mockgen
+        run: go install go.uber.org/mock/mockgen@latest
+
+      - name: Generate mocks
+        run: make generate-mocks
+
+      - name: Run tests
+        run: make run-tests

Makefile

@@ -0,0 +1,12 @@
+.PHONY: help
+help:
+	@awk 'BEGIN {FS = ":.*##"; printf "Usage: make \033[36m<target>\033[0m\n"} /^[a-zA-Z_-]+:.*?##/ { printf "  \033[36m%-10s\033[0m %s\n", $$1, $$2 } /^##@/ { printf "\n\033[1m%s\033[0m\n", substr($$0, 5) } ' $(MAKEFILE_LIST)
+
+.DEFAULT_GOAL := help
+
+##@ Tests
+generate-mocks: ## generate mock files using mockgen
+	go generate ./internal/server/services
+
+run-tests: ## run unit tests
+	go test -v -race ./...

README.md

@@ -6,7 +6,8 @@
 [![License](https://img.shields.io/badge/license-MIT-red.svg)](LICENSE)
 [![Go Version](https://img.shields.io/github/go-mod/go-version/TuanKiri/weather-mcp-server)](go.mod)
 [![Go Report Card](https://goreportcard.com/badge/github.com/TuanKiri/weather-mcp-server?cache)](https://goreportcard.com/report/github.com/TuanKiri/weather-mcp-server)
-[![Build](https://github.com/TuanKiri/weather-mcp-server/workflows/Build/badge.svg)](https://github.com/TuanKiri/weather-mcp-server/actions?workflow=Build)
+[![Build](https://github.com/TuanKiri/weather-mcp-server/actions/workflows/go.yml/badge.svg?branch=master)](https://github.com/TuanKiri/weather-mcp-server/actions?workflow=Build)
+[![Tests](https://github.com/TuanKiri/weather-mcp-server/actions/workflows/test.yml/badge.svg?branch=master)](https://github.com/TuanKiri/weather-mcp-server/actions?workflow=Test)
 
 <strong>[Report Bug](https://github.com/TuanKiri/weather-mcp-server/issues/new?assignees=&labels=bug&projects=&template=bug_report.yml)</strong> | <strong>[Request Feature](https://github.com/TuanKiri/weather-mcp-server/issues/new?assignees=&labels=enhancement&projects=&template=feature_request.yml)</strong>
 
@@ -29,7 +30,6 @@ To use your MCP server with Claude Desktop, add it to your Claude configuration:
   "mcpServers": {
     "weather-mcp-server": {
       "command": "/path/to/weather-mcp-server",
-      "args": [],
       "env": {
         "WEATHER_API_KEY": "your-api-key"
       }
@@ -62,7 +62,7 @@ go build -o weather-mcp-server ./cmd/weather-mcp-server
 
 ## Using MCP with Docker Containers
 
-#### 1. Build the Docker image:
+#### 1. Build the Docker Image:
 
 ```shell
 docker build -t weather-mcp-server .
@@ -100,6 +100,30 @@ The project is organized into several key directories:
 └── pkg
 ```
 
+## Testing
+
+If you're adding new features, please make sure to include tests for them.
+
+#### 1. Install the mockgen tool:
+
+```shell
+go install go.uber.org/mock/mockgen@latest
+```
+
+See the installation guide on [go.uber.org/mock](https://github.com/uber-go/mock?tab=readme-ov-file#installation).
+
+#### 2. Use the following command to generate mock files:
+
+```shell
+make generate-mocks
+```
+
+#### 3. To run unit tests:
+
+```shell
+make run-tests
+```
+
 ## Contributing
 
 Feel free to open tickets or send pull requests with improvements. Thanks in advance for your help!

go.mod

@@ -2,9 +2,16 @@ module github.com/TuanKiri/weather-mcp-server
 
 go 1.24.1
 
-require github.com/mark3labs/mcp-go v0.18.0
+require (
+	github.com/mark3labs/mcp-go v0.18.0
+	github.com/stretchr/testify v1.9.0
+	go.uber.org/mock v0.5.1
+)
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/uuid v1.6.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -10,5 +10,9 @@ github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsT
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 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=
+go.uber.org/mock v0.5.1 h1:ASgazW/qBmR+A32MYFDB6E2POoTgOwT509VP0CT/fjs=
+go.uber.org/mock v0.5.1/go.mod h1:ge71pBPLYDk7QIi1LupWxdAykm7KIEFchiOqd6z7qMM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/server/handlers/weather_test.go

@@ -0,0 +1,82 @@
+package handlers
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	"github.com/mark3labs/mcp-go/mcp"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/TuanKiri/weather-mcp-server/internal/server/services/mock"
+)
+
+func TestCurrentWeather(t *testing.T) {
+	testCases := map[string]struct {
+		arguments           map[string]any
+		errString           string
+		wait                string
+		setupWeatherService func(mocksWeather *mock.MockWeatherService)
+	}{
+		"empty_city": {
+			wait: "city must be a string",
+		},
+		"city_not_found": {
+			arguments: map[string]any{
+				"city": "Tokyo",
+			},
+			errString: "weather API not available. Code: 400",
+			setupWeatherService: func(mocksWeather *mock.MockWeatherService) {
+				mocksWeather.EXPECT().
+					Current(context.Background(), "Tokyo").
+					Return("", errors.New("weather API not available. Code: 400"))
+			},
+		},
+		"successful_request": {
+			arguments: map[string]any{
+				"city": "London",
+			},
+			wait: "<h1>London weather data</h1>",
+			setupWeatherService: func(mocksWeather *mock.MockWeatherService) {
+				mocksWeather.EXPECT().
+					Current(context.Background(), "London").
+					Return("<h1>London weather data</h1>", nil)
+			},
+		},
+	}
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	mocksWeather := mock.NewMockWeatherService(ctrl)
+
+	svc := mock.NewMockServices(ctrl)
+	svc.EXPECT().Weather().Return(mocksWeather).AnyTimes()
+
+	handler := CurrentWeather(svc)
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			if tc.setupWeatherService != nil {
+				tc.setupWeatherService(mocksWeather)
+			}
+
+			var request mcp.CallToolRequest
+			request.Params.Arguments = tc.arguments
+
+			result, err := handler(context.Background(), request)
+			if err != nil {
+				assert.EqualError(t, err, tc.errString)
+				return
+			}
+
+			require.Len(t, result.Content, 1)
+			content, ok := result.Content[0].(mcp.TextContent)
+			require.True(t, ok)
+
+			assert.Equal(t, tc.wait, content.Text)
+		})
+	}
+}

internal/server/services/core/core.go

@@ -4,17 +4,16 @@ import (
 	"html/template"
 
 	"github.com/TuanKiri/weather-mcp-server/internal/server/services"
-	"github.com/TuanKiri/weather-mcp-server/pkg/weatherapi"
 )
 
 type CoreServices struct {
 	renderer   *template.Template
-	weatherAPI *weatherapi.WeatherAPI
+	weatherAPI services.WeatherAPIProvider
 
 	weatherService *WeatherService
 }
 
-func New(renderer *template.Template, weatherAPI *weatherapi.WeatherAPI) *CoreServices {
+func New(renderer *template.Template, weatherAPI services.WeatherAPIProvider) *CoreServices {
 	return &CoreServices{
 		renderer:   renderer,
 		weatherAPI: weatherAPI,

internal/server/services/core/weather_test.go

@@ -0,0 +1,85 @@
+package core
+
+import (
+	"context"
+	"errors"
+	"html/template"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
+
+	"github.com/TuanKiri/weather-mcp-server/internal/server/services/mock"
+	"github.com/TuanKiri/weather-mcp-server/pkg/weatherapi/models"
+)
+
+func TestCurrentWeather(t *testing.T) {
+	testCases := map[string]struct {
+		city            string
+		errString       string
+		wait            string
+		setupWeatherAPI func(weatherAPI *mock.MockWeatherAPIProvider)
+	}{
+		"city_not_found": {
+			city:      "Tokyo",
+			errString: "weather API not available. Code: 400",
+			setupWeatherAPI: func(weatherAPI *mock.MockWeatherAPIProvider) {
+				weatherAPI.EXPECT().
+					Current(context.Background(), "Tokyo").
+					Return(nil, errors.New("weather API not available. Code: 400"))
+			},
+		},
+		"successful_result": {
+			city: "London",
+			wait: "London, United Kingdom Sunny 18 45 4 " +
+				"https://cdn.weatherapi.com/weather/64x64/day/113.png",
+			setupWeatherAPI: func(weatherAPI *mock.MockWeatherAPIProvider) {
+				weatherAPI.EXPECT().
+					Current(context.Background(), "London").
+					Return(&models.CurrentResponse{
+						Location: models.Location{
+							Name:    "London",
+							Country: "United Kingdom",
+						},
+						Current: models.Current{
+							TempC:    18.4,
+							WindKph:  4.2,
+							Humidity: 45,
+							Condition: models.Condition{
+								Text: "Sunny",
+								Icon: "//cdn.weatherapi.com/weather/64x64/day/113.png",
+							},
+						},
+					}, nil)
+			},
+		},
+	}
+
+	renderer, err := template.New("weather.html").Parse(
+		"{{ .Location }} {{ .Condition }} {{ .Temperature }} " +
+			"{{ .Humidity }} {{ .WindSpeed }} {{ .Icon }}")
+	require.NoError(t, err)
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	weatherAPI := mock.NewMockWeatherAPIProvider(ctrl)
+
+	svc := New(renderer, weatherAPI)
+
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			if tc.setupWeatherAPI != nil {
+				tc.setupWeatherAPI(weatherAPI)
+			}
+
+			data, err := svc.Weather().Current(context.Background(), tc.city)
+			if err != nil {
+				assert.EqualError(t, err, tc.errString)
+			}
+
+			assert.Equal(t, tc.wait, data)
+		})
+	}
+}

internal/server/services/external.go

@@ -0,0 +1,13 @@
+package services
+
+import (
+	"context"
+
+	"github.com/TuanKiri/weather-mcp-server/pkg/weatherapi/models"
+)
+
+//go:generate mockgen --source external.go --destination mock/external_mock.go --package mock
+
+type WeatherAPIProvider interface {
+	Current(ctx context.Context, city string) (*models.CurrentResponse, error)
+}

internal/server/services/mock/.gitignore

@@ -0,0 +1,2 @@
+*.go
+!.gitignore

internal/server/services/services.go

@@ -2,6 +2,8 @@ package services
 
 import "context"
 
+//go:generate mockgen --source services.go --destination mock/mock.go --package mock
+
 type Services interface {
 	Weather() WeatherService
 }

internal/server/tools/weather_test.go

@@ -0,0 +1,18 @@
+package tools
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCurrentWeather(t *testing.T) {
+	tool, handler := CurrentWeather(nil)
+
+	assert.Equal(t, "current_weather", tool.Name)
+	assert.NotEmpty(t, tool.Description)
+	assert.Contains(t, tool.InputSchema.Properties, "city")
+	assert.ElementsMatch(t, tool.InputSchema.Required, []string{"city"})
+
+	assert.NotNil(t, handler)
+}