feat: initial release with 48 Mattermost MCP tools

- 27 base tools: channels, messaging, users, reactions, files, DMs
- Team management: invite/remove users, get stats, list members
- Slash commands: execute /remind, /poll, etc.
- Webhook management: incoming and outgoing webhooks
- System tools: server config, logs, bulk status updates
- Channel admin: create, invite, leave, delete channels
- Read-only mode for safe exploration
- Dual token support (bot + PAT) for enhanced security
- Apache 2.0 licensed

operation/dm/dm_test.go

@@ -0,0 +1,77 @@
+package dm
+
+import (
+	"testing"
+
+	"github.com/karti-ai/mattermost-mcp-server/pkg/mattermost"
+	"github.com/mark3labs/mcp-go/mcp"
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestSlimChannel(t *testing.T) {
+	c := &model.Channel{
+		Id:          "channel123",
+		Name:        "user1__user2",
+		DisplayName: "user1, user2",
+		Type:        model.ChannelTypeDirect,
+		TeamId:      "",
+	}
+
+	slim := SlimChannel(c)
+	assert.NotNil(t, slim)
+	assert.Equal(t, "channel123", slim["id"])
+	assert.Equal(t, "user1__user2", slim["name"])
+	assert.Equal(t, "user1, user2", slim["display_name"])
+	assert.Equal(t, model.ChannelTypeDirect, slim["type"])
+	assert.Equal(t, "", slim["team_id"])
+}
+
+func TestSlimChannel_Nil(t *testing.T) {
+	slim := SlimChannel(nil)
+	assert.Nil(t, slim)
+}
+
+func TestToolRegistration(t *testing.T) {
+	tools := Tool.Tools()
+	assert.Len(t, tools, 1)
+
+	toolNames := make(map[string]bool)
+	for _, t := range tools {
+		toolNames[t.Tool.Name] = true
+	}
+
+	assert.True(t, toolNames[CreateDMToolName], "CreateDM tool should be registered")
+}
+
+func TestCreateDMFn_ClientNotInitialized(t *testing.T) {
+	mattermost.SetGlobalClient(nil)
+
+	req := mcp.CallToolRequest{
+		Params: mcp.CallToolParams{
+			Name: CreateDMToolName,
+			Arguments: map[string]interface{}{
+				"user_id": "user123",
+			},
+		},
+	}
+
+	result, err := CreateDMFn(nil, req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.True(t, result.IsError)
+}
+
+func TestCreateDMFn_MissingUserId(t *testing.T) {
+	req := mcp.CallToolRequest{
+		Params: mcp.CallToolParams{
+			Name:      CreateDMToolName,
+			Arguments: map[string]interface{}{},
+		},
+	}
+
+	result, err := CreateDMFn(nil, req)
+	assert.NoError(t, err)
+	assert.NotNil(t, result)
+	assert.True(t, result.IsError)
+}