2 files changed, 166 insertions, 1 deletions
diff --git a/go/internal/command/discover/discover.go b/go/internal/command/discover/discover.go
index 63a7a32..ab04cbd 100644
--- a/go/internal/command/discover/discover.go
+++ b/go/internal/command/discover/discover.go
@@ -2,9 +2,12 @@ package discover
 
 import (
 	"fmt"
+	"io"
+	"os"
 
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/commandargs"
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/config"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/gitlabnet/discover"
 )
 
 type Command struct {
@@ -12,6 +15,38 @@ type Command struct {
 	Args   *commandargs.CommandArgs
 }
 
+var (
+	output io.Writer = os.Stdout
+)
+
 func (c *Command) Execute() error {
-	return fmt.Errorf("No feature is implemented yet")
+	response, err := c.getUserInfo()
+	if err != nil {
+		return fmt.Errorf("Failed to get username: %v", err)
+	}
+
+	if response.IsAnonymous() {
+		fmt.Fprintf(output, "Welcome to GitLab, Anonymous!\n")
+	} else {
+		fmt.Fprintf(output, "Welcome to GitLab, @%s!\n", response.Username)
+	}
+
+	return nil
+}
+
+func (c *Command) getUserInfo() (*discover.Response, error) {
+	client, err := discover.NewClient(c.Config)
+	if err != nil {
+		return nil, err
+	}
+
+	if c.Args.GitlabKeyId != "" {
+		return client.GetByKeyId(c.Args.GitlabKeyId)
+	} else if c.Args.GitlabUsername != "" {
+		return client.GetByUsername(c.Args.GitlabUsername)
+	} else {
+		// There was no 'who' information, this  matches the ruby error
+		// message.
+		return nil, fmt.Errorf("who='' is invalid")
+	}
 }
diff --git a/go/internal/command/discover/discover_test.go b/go/internal/command/discover/discover_test.go
new file mode 100644
index 0000000..752e76e
--- /dev/null
+++ b/go/internal/command/discover/discover_test.go
@@ -0,0 +1,130 @@
+package discover
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/commandargs"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/config"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/gitlabnet/testserver"
+)
+
+var (
+	testConfig = &config.Config{GitlabUrl: "http+unix://" + testserver.TestSocket}
+	requests   = []testserver.TestRequestHandler{
+		{
+			Path: "/api/v4/internal/discover",
+			Handler: func(w http.ResponseWriter, r *http.Request) {
+				if r.URL.Query().Get("key_id") == "1" || r.URL.Query().Get("username") == "alex-doe" {
+					body := map[string]interface{}{
+						"id":       2,
+						"username": "alex-doe",
+						"name":     "Alex Doe",
+					}
+					json.NewEncoder(w).Encode(body)
+				} else if r.URL.Query().Get("username") == "broken_message" {
+					body := map[string]string{
+						"message": "Forbidden!",
+					}
+					w.WriteHeader(http.StatusForbidden)
+					json.NewEncoder(w).Encode(body)
+				} else if r.URL.Query().Get("username") == "broken" {
+					w.WriteHeader(http.StatusInternalServerError)
+				} else {
+					fmt.Fprint(w, "null")
+				}
+			},
+		},
+	}
+)
+
+func TestExecute(t *testing.T) {
+	cleanup, err := testserver.StartSocketHttpServer(requests)
+	require.NoError(t, err)
+	defer cleanup()
+
+	testCases := []struct {
+		desc           string
+		arguments      *commandargs.CommandArgs
+		expectedOutput string
+	}{
+		{
+			desc:           "With a known username",
+			arguments:      &commandargs.CommandArgs{GitlabUsername: "alex-doe"},
+			expectedOutput: "Welcome to GitLab, @alex-doe!\n",
+		},
+		{
+			desc:           "With a known key id",
+			arguments:      &commandargs.CommandArgs{GitlabKeyId: "1"},
+			expectedOutput: "Welcome to GitLab, @alex-doe!\n",
+		},
+		{
+			desc:           "With an unknown key",
+			arguments:      &commandargs.CommandArgs{GitlabKeyId: "-1"},
+			expectedOutput: "Welcome to GitLab, Anonymous!\n",
+		},
+		{
+			desc:           "With an unknown username",
+			arguments:      &commandargs.CommandArgs{GitlabUsername: "unknown"},
+			expectedOutput: "Welcome to GitLab, Anonymous!\n",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			buffer := &bytes.Buffer{}
+			output = buffer
+			cmd := &Command{Config: testConfig, Args: tc.arguments}
+
+			err := cmd.Execute()
+
+			assert.NoError(t, err)
+			assert.Equal(t, tc.expectedOutput, buffer.String())
+		})
+	}
+}
+
+func TestFailingExecute(t *testing.T) {
+	cleanup, err := testserver.StartSocketHttpServer(requests)
+	require.NoError(t, err)
+	defer cleanup()
+
+	testCases := []struct {
+		desc          string
+		arguments     *commandargs.CommandArgs
+		expectedError string
+	}{
+		{
+			desc:          "With missing arguments",
+			arguments:     &commandargs.CommandArgs{},
+			expectedError: "Failed to get username: who='' is invalid",
+		},
+		{
+			desc:          "When the API returns an error",
+			arguments:     &commandargs.CommandArgs{GitlabUsername: "broken_message"},
+			expectedError: "Failed to get username: Forbidden!",
+		},
+		{
+			desc:          "When the API fails",
+			arguments:     &commandargs.CommandArgs{GitlabUsername: "broken"},
+			expectedError: "Failed to get username: Internal API error (500)",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			cmd := &Command{Config: testConfig, Args: tc.arguments}
+
+			err := cmd.Execute()
+
+			assert.EqualError(t, err, tc.expectedError)
+		})
+	}
+
+}