Add cmd follow test

cmd/mstdn/cmd_follow_test.go

@@ -14,8 +14,17 @@ func TestCmdFollow(t *testing.T) {
 		func(w http.ResponseWriter, r *http.Request) {
 			switch r.URL.Path {
 			case "/api/v1/accounts/search":
-				fmt.Fprintln(w, `[{"id": 123}]`)
-				return
+				q := r.URL.Query().Get("q")
+				if q == "mattn" {
+					fmt.Fprintln(w, `[{"id": 123}]`)
+					return
+				} else if q == "different_id" {
+					fmt.Fprintln(w, `[{"id": 1234567}]`)
+					return
+				} else if q == "empty" {
+					fmt.Fprintln(w, `[]`)
+					return
+				}
 			case "/api/v1/accounts/123/follow":
 				fmt.Fprintln(w, `{"id": 123}`)
 				ok = true
@@ -25,7 +34,34 @@ func TestCmdFollow(t *testing.T) {
 			return
 		},
 		func(app *cli.App) {
-			app.Run([]string{"mstdn", "follow", "mattn"})
+			err := app.Run([]string{"mstdn", "follow", "mattn"})
+			if err != nil {
+				t.Fatalf("should not be fail: %v", err)
+			}
+		},
+		func(app *cli.App) {
+			err := app.Run([]string{"mstdn", "follow"})
+			if err == nil {
+				t.Fatalf("should be fail: %v", err)
+			}
+		},
+		func(app *cli.App) {
+			err := app.Run([]string{"mstdn", "follow", "fail"})
+			if err == nil {
+				t.Fatalf("should be fail: %v", err)
+			}
+		},
+		func(app *cli.App) {
+			err := app.Run([]string{"mstdn", "follow", "empty"})
+			if err != nil {
+				t.Fatalf("should not be fail: %v", err)
+			}
+		},
+		func(app *cli.App) {
+			err := app.Run([]string{"mstdn", "follow", "different_id"})
+			if err == nil {
+				t.Fatalf("should not be fail: %v", err)
+			}
 		},
 	)
 	if !ok {

cmd/mstdn/cmd_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/urfave/cli"
 )
 
-func testWithServer(h http.HandlerFunc, testFunc func(*cli.App)) string {
+func testWithServer(h http.HandlerFunc, testFuncs ...func(*cli.App)) string {
 	ts := httptest.NewServer(h)
 	defer ts.Close()
 
@@ -31,6 +31,10 @@ func testWithServer(h http.HandlerFunc, testFunc func(*cli.App)) string {
 			Server: "https://example.com",
 		},
 	}
-	testFunc(app)
+
+	for _, f := range testFuncs {
+		f(app)
+	}
+
 	return buf.String()
 }