new checker suite-broken-parallel (#118)

* suite-broken-parallel: debug cases

* new checker 'suite-broken-parallel'

* suite-broken-parallel: self-review

Author: Antonboom

README.md

@@ -103,6 +103,7 @@ https://golangci-lint.run/usage/linters/#testifylint
 | [negative-positive](#negative-positive)             | ✅                  | ✅       |
 | [nil-compare](#nil-compare)                         | ✅                  | ✅       |
 | [require-error](#require-error)                     | ✅                  | ❌       |
+| [suite-broken-parallel](#suite-broken-parallel)     | ✅                  | ✅       |
 | [suite-dont-use-pkg](#suite-dont-use-pkg)           | ✅                  | ✅       |
 | [suite-extra-assert-call](#suite-extra-assert-call) | ✅                  | ✅       |
 | [suite-subtest-run](#suite-subtest-run)             | ✅                  | ❌       |
@@ -667,11 +668,61 @@ Also, to minimize false positives, `require-error` ignores:
 
 ---
 
-### suite-dont-use-pkg
+### suite-broken-parallel
 
 ```go
-import "github.com/stretchr/testify/assert"
+func (s *MySuite) SetupTest() {
+    s.T().Parallel() ❌
+}
+
+// And other hooks...
+
+func (s *MySuite) TestSomething() {
+    s.T().Parallel() ❌
+    
+    for _, tt := range cases {
+        s.Run(tt.name, func() {
+            s.T().Parallel() ❌
+        })
+        
+        s.T().Run(tt.name, func(t *testing.T) {
+            t.Parallel() ❌
+        })
+    }
+}
+```
+
+**Autofix**: true. <br>
+**Enabled by default**: true. <br>
+**Reason**: Protection from undefined behaviour.
+
+`v1` of `testify` doesn't support suite's parallel tests and subtests.
+
+Depending on [case](./analyzer/testdata/src/debug/suite_broken_parallel_test.go) using of `t.Parallel()` leads to
 
+- data race
+- panic
+- non-working suite hooks
+- silent ignoring of this directive
+
+So, `testify`'s maintainers recommend discourage parallel tests inside suite.
+
+<details>
+<summary>Related issues...</summary>
+
+- https://github.com/stretchr/testify/issues/187
+- https://github.com/stretchr/testify/issues/466
+- https://github.com/stretchr/testify/issues/934
+- https://github.com/stretchr/testify/issues/1139
+- https://github.com/stretchr/testify/issues/1253
+
+</details>
+
+---
+
+### suite-dont-use-pkg
+
+```go
 func (s *MySuite) TestSomething() {
     ❌ assert.Equal(s.T(), 42, value)
     ✅ s.Equal(42, value)

analyzer/checkers_factory_test.go

@@ -51,12 +51,14 @@ func Test_newCheckers(t *testing.T) {
 		checkers.NewBlankImport(),
 		checkers.NewGoRequire(),
 		checkers.NewRequireError(),
+		checkers.NewSuiteBrokenParallel(),
 		checkers.NewSuiteSubtestRun(),
 	}
 	allAdvancedCheckers := []checkers.AdvancedChecker{
 		checkers.NewBlankImport(),
 		checkers.NewGoRequire(),
 		checkers.NewRequireError(),
+		checkers.NewSuiteBrokenParallel(),
 		checkers.NewSuiteSubtestRun(),
 		checkers.NewSuiteTHelper(),
 	}

analyzer/testdata/src/checkers-default/suite-broken-parallel/suite_broken_parallel_test.go

@@ -0,0 +1,83 @@
+// Code generated by testifylint/internal/testgen. DO NOT EDIT.
+
+package suitebrokenparallel
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+)
+
+type SuiteBrokenParallelCheckerSuite struct {
+	suite.Suite
+}
+
+func TestSuiteBrokenParallelCheckerSuite(t *testing.T) {
+	t.Parallel()
+	suite.Run(t, new(SuiteBrokenParallelCheckerSuite))
+}
+
+func (s *SuiteBrokenParallelCheckerSuite) BeforeTest(_, _ string) {
+}
+
+func (s *SuiteBrokenParallelCheckerSuite) SetupTest() {
+}
+
+func (s *SuiteBrokenParallelCheckerSuite) TestAll() {
+
+	s.Run("", func() {
+		s.Equal(1, 2)
+	})
+
+	s.T().Run("", func(t *testing.T) {
+		assert.Equal(t, 1, 2)
+	})
+
+	s.Run("", func() {
+		s.Equal(1, 2)
+
+		s.Run("", func() {
+			s.Equal(1, 2)
+
+			s.Run("", func() {
+				s.Equal(1, 2)
+			})
+
+			s.T().Run("", func(t *testing.T) {
+				assert.Equal(t, 1, 2)
+			})
+		})
+	})
+}
+
+func (s *SuiteBrokenParallelCheckerSuite) TestTable() {
+	cases := []struct{ Name string }{}
+
+	for _, tt := range cases {
+		tt := tt
+		s.T().Run(tt.Name, func(t *testing.T) {
+			s.Equal(1, 2)
+		})
+	}
+
+	for _, tt := range cases {
+		tt := tt
+		s.Run(tt.Name, func() {
+			s.Equal(1, 2)
+		})
+	}
+}
+
+func TestSimpleTable(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct{ Name string }{}
+	for _, tt := range cases {
+		tt := tt
+		t.Run(tt.Name, func(t *testing.T) {
+			t.Parallel()
+			assert.Equal(t, 1, 2)
+		})
+	}
+}