handle unknown languages

Author: lcowell

api/api.go

@@ -3,6 +3,7 @@ package api
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"strings"
@@ -14,6 +15,8 @@ var (
 	// UserAgent lets the API know where the call is being made from.
 	// It's set from main() so that we have access to the version.
 	UserAgent string
+
+	UnknownLanguageError = errors.New("the language is unknown")
 )
 
 // PayloadError represents an error message from the API.
@@ -143,6 +146,9 @@ func List(language, host string) ([]string, error) {
 		return nil, err
 	}
 	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		return nil, UnknownLanguageError
+	}
 
 	var payload struct {
 		Track Track

api/api_test.go

@@ -30,3 +30,13 @@ func TestListTrack(t *testing.T) {
 	assert.Equal(t, len(problems), 34)
 	assert.Equal(t, problems[0], "bob")
 }
+
+func TestUnknownLanguage(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.NotFound(w, r)
+	}))
+	defer ts.Close()
+
+	_, err := List("rubbbby", ts.URL)
+	assert.Equal(t, err, UnknownLanguageError)
+}