Drop From field validation check

Currently if From.Name is zero the validation wrongly reports that the From field is required. Drop the From field validation check as it's not so useful.

Author: Kargakis

pkg/build/api/validation/validation.go

@@ -240,8 +240,6 @@ func validateImageChange(imageChange *buildapi.ImageChangeTrigger) errs.Validati
 		allErrs = append(allErrs, errs.NewFieldRequired("image"))
 	}
 	if len(imageChange.From.Name) == 0 {
-		allErrs = append(allErrs, errs.NewFieldRequired("from"))
-	} else if len(imageChange.From.Name) == 0 {
 		allErrs = append(allErrs, errs.ValidationErrorList{errs.NewFieldRequired("name")}.Prefix("from")...)
 	}
 	return allErrs

pkg/build/api/validation/validation_test.go

@@ -505,3 +505,66 @@ func TestValidateTrigger(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateImageChange(t *testing.T) {
+	tests := []struct {
+		name           string
+		ict            *buildapi.ImageChangeTrigger
+		expectedErrNum int
+	}{
+		{
+			name: "Pass",
+			ict: &buildapi.ImageChangeTrigger{
+				Image: "openshift",
+				From: kapi.ObjectReference{
+					Name: "default/repo",
+				},
+			},
+			expectedErrNum: 0,
+		},
+		{
+			name: "Missing image ref",
+			ict: &buildapi.ImageChangeTrigger{
+				Image: "",
+				From: kapi.ObjectReference{
+					Name: "default/repo",
+				},
+			},
+			expectedErrNum: 1,
+		},
+		{
+			name: "Missing From ref",
+			ict: &buildapi.ImageChangeTrigger{
+				Image: "openshift",
+				From: kapi.ObjectReference{
+					Name: "",
+				},
+			},
+			expectedErrNum: 1,
+		},
+		{
+			name: "Both missing refs",
+			ict: &buildapi.ImageChangeTrigger{
+				Image: "",
+				From: kapi.ObjectReference{
+					Name: "",
+				},
+			},
+			expectedErrNum: 2,
+		},
+		{
+			name: "Undefined from field",
+			ict: &buildapi.ImageChangeTrigger{
+				Image: "openshift",
+			},
+			expectedErrNum: 1,
+		},
+	}
+
+	for _, test := range tests {
+		got := len(validateImageChange(test.ict))
+		if test.expectedErrNum != got {
+			t.Errorf("%s: Expected %d error(s), got %d", test.name, test.expectedErrNum, got)
+		}
+	}
+}