config: add tests for validation errors

config/config_test.go

@@ -0,0 +1,138 @@
+package config_test
+
+import (
+	"fmt"
+	"os"
+	"testing"
+
+	"github.com/MakeNowJust/heredoc"
+	"github.com/raystack/raccoon/config"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLoad(t *testing.T) {
+	var testCases = []struct {
+		Desc string
+		Cfg  string
+		Err  error
+	}{
+		{
+			Desc: "should return an error if websocket.conn.id.header is not specified",
+			Err: config.ConfigError{
+				Env:  "SERVER_WEBSOCKET_CONN_ID_HEADER",
+				Flag: "server.websocket.conn.id.header",
+			},
+		},
+		{
+			Desc: "should return an error if publisher type is pubsub and ProjectID is not specified",
+			Cfg: heredoc.Doc(`
+				server:
+				  websocket:
+				    conn:
+				      id_header: "X-User-ID"
+				publisher:
+				  type: "pubsub"
+			`),
+			Err: config.ConfigError{
+				Env:  "PUBLISHER_PUBSUB_PROJECT_ID",
+				Flag: "publisher.pubsub.project.id",
+			},
+		},
+		{
+			Desc: "should return an error if publisher type is pubsub and credentials are not specified",
+			Cfg: heredoc.Doc(`
+				server:
+				  websocket:
+				    conn:
+				      id_header: "X-User-ID"
+				publisher:
+				  type: "pubsub"
+				  pubsub:
+				    project_id: simulated-project-001
+			`),
+			Err: config.ConfigError{
+				Env:  "PUBLISHER_PUBSUB_CREDENTIALS",
+				Flag: "publisher.pubsub.credentials",
+			},
+		},
+		{
+			Desc: "should return an error if publisher type is kinesis and credentials are not specified",
+			Cfg: heredoc.Doc(`
+				server:
+				  websocket:
+				    conn:
+				      id_header: "X-User-ID"
+				publisher:
+				  type: "kinesis"
+			`),
+			Err: config.ConfigError{
+				Env:  "PUBLISHER_KINESIS_CREDENTIALS",
+				Flag: "publisher.kinesis.credentials",
+			},
+		},
+		{
+			Desc: "should return an error if publisher type is kafka and bootstrap servers are not specified",
+			Cfg: heredoc.Doc(`
+				server:
+				  websocket:
+				    conn:
+				      id_header: "X-User-ID"
+				publisher:
+				  type: "kafka"
+			`),
+			Err: config.ConfigError{
+				Env:  "PUBLISHER_KAFKA_CLIENT_BOOTSTRAP_SERVERS",
+				Flag: "publisher.kafka.client.bootstrap.servers",
+			},
+		},
+		{
+			Desc: "should return an error if an unknown publisher type is specified",
+			Cfg: heredoc.Doc(`
+				server:
+				  websocket:
+				    conn:
+				      id_header: "X-User-ID"
+				publisher:
+				  type: "non-existent"
+			`),
+			Err: fmt.Errorf("unknown publisher: non-existent"),
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.Desc, func(t *testing.T) {
+			fd, err := newTempFile()
+			if err != nil {
+				t.Errorf("error creating temporary file: %v", err)
+				return
+			}
+			defer fd.Close()
+
+			_, err = fmt.Fprint(fd, testCase.Cfg)
+			if err != nil {
+				t.Errorf("error writing test config: %v", err)
+				return
+			}
+
+			err = config.Load(fd.Name())
+			assert.Equal(t, err, testCase.Err)
+		})
+	}
+}
+
+type tempFile struct {
+	*os.File
+}
+
+func (f tempFile) Close() error {
+	f.File.Close()
+	return os.Remove(f.File.Name())
+}
+
+func newTempFile() (tempFile, error) {
+	fd, err := os.CreateTemp("", "raccoon-test-*")
+	if err != nil {
+		return tempFile{}, err
+	}
+	return tempFile{fd}, nil
+}

config/errors.go

@@ -60,9 +60,13 @@ func errCfgRequired(path string) error {
 	if err != nil {
 		return err
 	}
-	return errRequired(env, cmd)
+	return ConfigError{env, cmd}
 }
 
-func errRequired(env, cmd string) error {
-	return fmt.Errorf("%s (--%s) is required", env, cmd)
+type ConfigError struct {
+	Env, Flag string
+}
+
+func (e ConfigError) Error() string {
+	return fmt.Sprintf("%s (--%s) is required", e.Env, e.Flag)
 }