added check for empty source in bind mount

Signed-off-by: Ethan Haynes <ethanhaynes@alumni.harvard.edu>

fixed error by removing punctuation

Signed-off-by: Ethan Haynes <ethanhaynes@alumni.harvard.edu>

cli/compose/loader/loader.go

@@ -337,7 +337,9 @@ func LoadService(name string, serviceDict map[string]interface{}, workingDir str
 		return nil, err
 	}
 
-	resolveVolumePaths(serviceConfig.Volumes, workingDir, lookupEnv)
+	if err := resolveVolumePaths(serviceConfig.Volumes, workingDir, lookupEnv); err != nil {
+		return nil, err
+	}
 	return serviceConfig, nil
 }
 
@@ -376,12 +378,16 @@ func resolveEnvironment(serviceConfig *types.ServiceConfig, workingDir string, l
 	return nil
 }
 
-func resolveVolumePaths(volumes []types.ServiceVolumeConfig, workingDir string, lookupEnv template.Mapping) {
+func resolveVolumePaths(volumes []types.ServiceVolumeConfig, workingDir string, lookupEnv template.Mapping) error {
 	for i, volume := range volumes {
 		if volume.Type != "bind" {
 			continue
 		}
 
+		if volume.Source == "" {
+			return errors.New("invalid mount config for type \"bind\": field Source must not be empty.")
+		}
+
 		filePath := expandUser(volume.Source, lookupEnv)
 		// Check for a Unix absolute path first, to handle a Windows client
 		// with a Unix daemon. This handles a Windows client connecting to a
@@ -394,6 +400,7 @@ func resolveVolumePaths(volumes []types.ServiceVolumeConfig, workingDir string,
 		volume.Source = filePath
 		volumes[i] = volume
 	}
+	return nil
 }
 
 // TODO: make this more robust

cli/compose/loader/loader_test.go

@@ -1266,6 +1266,47 @@ services:
 	assert.Contains(t, err.Error(), "services.tmpfs.volumes.0 Additional property tmpfs is not allowed")
 }
 
+func TestLoadBindMountSourceMustNotBeEmpty(t *testing.T) {
+	_, err := loadYAML(`
+version: "3.5"
+services:
+  tmpfs:
+    image: nginx:latest
+    volumes:
+      - type: bind
+        target: /app
+`)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "invalid mount config for type \"bind\": field Source must not be empty")
+}
+
+func TestLoadBindMountWithSource(t *testing.T) {
+	config, err := loadYAML(`
+version: "3.5"
+services:
+  bind:
+    image: nginx:latest
+    volumes:
+      - type: bind
+        target: /app
+        source: "."
+`)
+	require.NoError(t, err)
+
+	workingDir, err := os.Getwd()
+	require.NoError(t, err)
+
+	expected := types.ServiceVolumeConfig{
+		Type:   "bind",
+		Source: workingDir,
+		Target: "/app",
+	}
+
+	require.Len(t, config.Services, 1)
+	assert.Len(t, config.Services[0].Volumes, 1)
+	assert.Equal(t, expected, config.Services[0].Volumes[0])
+}
+
 func TestLoadTmpfsVolumeSizeCanBeZero(t *testing.T) {
 	config, err := loadYAML(`
 version: "3.6"