error-nil: support empty and notempty error

README.md

@@ -307,6 +307,10 @@ logic, but without autofix.
 ❌
 assert.Nil(t, err)
 assert.NotNil(t, err)
+assert.Empty(t, err)
+assert.NotEmpty(t, err)
+assert.Zero(t, err)
+assert.NotZero(t, err)
 assert.Equal(t, nil, err)
 assert.EqualValues(t, nil, err)
 assert.Exactly(t, nil, err)

analyzer/testdata/src/checkers-default/error-nil/error_nil_test.go.golden

@@ -15,6 +15,14 @@ func TestErrorNilChecker(t *testing.T) {
 
 	// Invalid.
 	{
+		assert.NoError(t, err)                                   // want "error-nil: use assert\\.NoError"
+		assert.NoErrorf(t, err, "msg with args %d %s", 42, "42") // want "error-nil: use assert\\.NoErrorf"
+		assert.Error(t, err)                                     // want "error-nil: use assert\\.Error"
+		assert.Errorf(t, err, "msg with args %d %s", 42, "42")   // want "error-nil: use assert\\.Errorf"
+		assert.NoError(t, err)                                   // want "error-nil: use assert\\.NoError"
+		assert.NoErrorf(t, err, "msg with args %d %s", 42, "42") // want "error-nil: use assert\\.NoErrorf"
+		assert.Error(t, err)                                     // want "error-nil: use assert\\.Error"
+		assert.Errorf(t, err, "msg with args %d %s", 42, "42")   // want "error-nil: use assert\\.Errorf"
 		assert.NoError(t, err)                                   // want "error-nil: use assert\\.NoError"
 		assert.NoErrorf(t, err, "msg with args %d %s", 42, "42") // want "error-nil: use assert\\.NoErrorf"
 		assert.Error(t, err)                                     // want "error-nil: use assert\\.Error"
@@ -67,6 +75,14 @@ func TestErrorNilChecker(t *testing.T) {
 		assert.NotEqualf(t, err, err, "msg with args %d %s", 42, "42")
 		assert.NotEqual(t, nil, nil)
 		assert.NotEqualf(t, nil, nil, "msg with args %d %s", 42, "42")
+		assert.Empty(t, err.Error())
+		assert.Emptyf(t, err.Error(), "msg with args %d %s", 42, "42")
+		assert.NotEmpty(t, err.Error())
+		assert.NotEmptyf(t, err.Error(), "msg with args %d %s", 42, "42")
+		assert.Zero(t, err.Error())
+		assert.Zerof(t, err.Error(), "msg with args %d %s", 42, "42")
+		assert.NotZero(t, err.Error())
+		assert.NotZerof(t, err.Error(), "msg with args %d %s", 42, "42")
 	}
 }
 

internal/checkers/error_nil.go

@@ -13,6 +13,10 @@ import (
 //
 //	assert.Nil(t, err)
 //	assert.NotNil(t, err)
+//	assert.Empty(t, err)
+//	assert.NotEmpty(t, err)
+//	assert.Zero(t, err)
+//	assert.NotZero(t, err)
 //	assert.Equal(t, nil, err)
 //	assert.EqualValues(t, nil, err)
 //	assert.Exactly(t, nil, err)
@@ -40,12 +44,12 @@ func (checker ErrorNil) Check(pass *analysis.Pass, call *CallMeta) *analysis.Dia
 
 	proposedFn, survivingArg, replacementEndPos := func() (string, ast.Expr, token.Pos) {
 		switch call.Fn.NameFTrimmed {
-		case "Nil":
+		case "Nil", "Empty", "Zero":
 			if len(call.Args) >= 1 && isError(pass, call.Args[0]) {
 				return noErrorFn, call.Args[0], call.Args[0].End()
 			}
 
-		case "NotNil":
+		case "NotNil", "NotEmpty", "NotZero":
 			if len(call.Args) >= 1 && isError(pass, call.Args[0]) {
 				return errorFn, call.Args[0], call.Args[0].End()
 			}

internal/testgen/gen_error_nil.go

@@ -52,6 +52,10 @@ func (g ErrorNilTestsGenerator) TemplateData() any {
 		InvalidAssertions: []Assertion{
 			{Fn: "Nil", Argsf: "err", ReportMsgf: report, ProposedFn: "NoError"},
 			{Fn: "NotNil", Argsf: "err", ReportMsgf: report, ProposedFn: "Error"},
+			{Fn: "Empty", Argsf: "err", ReportMsgf: report, ProposedFn: "NoError"},
+			{Fn: "NotEmpty", Argsf: "err", ReportMsgf: report, ProposedFn: "Error"},
+			{Fn: "Zero", Argsf: "err", ReportMsgf: report, ProposedFn: "NoError"},
+			{Fn: "NotZero", Argsf: "err", ReportMsgf: report, ProposedFn: "Error"},
 			{Fn: "Equal", Argsf: "err, nil", ReportMsgf: report, ProposedFn: "NoError", ProposedArgsf: "err"},
 			{Fn: "Equal", Argsf: "nil, err", ReportMsgf: report, ProposedFn: "NoError", ProposedArgsf: "err"},
 			{Fn: "EqualValues", Argsf: "err, nil", ReportMsgf: report, ProposedFn: "NoError", ProposedArgsf: "err"},
@@ -76,6 +80,10 @@ func (g ErrorNilTestsGenerator) TemplateData() any {
 			{Fn: "Equal", Argsf: "nil, nil"},
 			{Fn: "NotEqual", Argsf: "err, err"},
 			{Fn: "NotEqual", Argsf: "nil, nil"},
+			{Fn: "Empty", Argsf: "err.Error()"},    // Requested by https://github.com/Antonboom/testifylint/issues/138
+			{Fn: "NotEmpty", Argsf: "err.Error()"}, // Requested by https://github.com/Antonboom/testifylint/issues/138
+			{Fn: "Zero", Argsf: "err.Error()"},     // Requested by https://github.com/Antonboom/testifylint/issues/138
+			{Fn: "NotZero", Argsf: "err.Error()"},  // Requested by https://github.com/Antonboom/testifylint/issues/138
 		},
 	}
 }