refactor: clean up form binding & validation (#38873)

Clarify the "validation" and "error display" logic.

All the copied&pasted `Validate` functions are removed.

modules/validation/binding_test.go

@@ -37,13 +37,7 @@ func performValidationTest(t *testing.T, testCase validationTestCase) {
 	m := chi.NewRouter()
 
 	m.Post(testRoute, func(resp http.ResponseWriter, req *http.Request) {
-		actual := binding.Validate(req, testCase.data)
-		// see https://github.com/stretchr/testify/issues/435
-		if actual == nil {
-			actual = binding.Errors{}
-		}
-
-		assert.Equal(t, testCase.expectedErrors, actual)
+		assert.Equal(t, testCase.expectedErrors, binding.Validate(req, testCase.data))
 	})
 
 	req, err := http.NewRequest(http.MethodPost, testRoute, nil)

modules/validation/glob_pattern_test.go

@@ -29,14 +29,12 @@ func Test_GlobPatternValidation(t *testing.T) {
 			data: TestForm{
 				GlobPattern: "",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "Valid glob",
 			data: TestForm{
 				GlobPattern: "{master,release*}",
 			},
-			expectedErrors: binding.Errors{},
 		},
 
 		{

modules/validation/refname_test.go

@@ -17,21 +17,18 @@ func Test_GitRefNameValidation(t *testing.T) {
 			data: TestForm{
 				BranchName: "test",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "Reference name contains single slash",
 			data: TestForm{
 				BranchName: "feature/test",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "Reference name has allowed special characters",
 			data: TestForm{
 				BranchName: "debian/1%1.6.0-2",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "Reference name contains backslash",

modules/validation/regex_pattern_test.go

@@ -26,14 +26,12 @@ func Test_RegexPatternValidation(t *testing.T) {
 			data: TestForm{
 				RegexPattern: "",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "Valid regex",
 			data: TestForm{
 				RegexPattern: `(\d{1,3})+`,
 			},
-			expectedErrors: binding.Errors{},
 		},
 
 		{

modules/validation/validurl_test.go

@@ -18,35 +18,30 @@ func Test_ValidURLValidation(t *testing.T) {
 			data: TestForm{
 				URL: "",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "URL without port",
 			data: TestForm{
 				URL: "http://test.lan/",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "URL with port",
 			data: TestForm{
 				URL: "http://test.lan:3000/",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "URL with IPv6 address without port",
 			data: TestForm{
 				URL: "http://[::1]/",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "URL with IPv6 address with port",
 			data: TestForm{
 				URL: "http://[::1]:3000/",
 			},
-			expectedErrors: binding.Errors{},
 		},
 		{
 			description: "Invalid URL",