diff options
author | Will Chandler <wchandler@gitlab.com> | 2023-08-24 15:32:43 +0300 |
---|---|---|
committer | Will Chandler <wchandler@gitlab.com> | 2023-08-30 16:39:24 +0300 |
commit | 3adbbfb5a6f8ff81590693d19f8c9828af1b7d45 (patch) | |
tree | f296a426454be57755fa53ba7405a7738c156396 /tools/golangci-lint/gitaly | |
parent | 534faf1e47f9e324afa38069393aef75d19a53ea (diff) |
lint: Add linter for testhelper.Run
Our tests will check for leaked goroutines, but only if `testhelper.Run`
is called in the package being tested. A recent production outage was
caused by leaked goroutines which our tests did not catch as the package
did not use the required helper.
Create a custom linter to validate the following:
- Each package that has tests also contains a `TestMain`.
- `TestMain` calls `testhelper.Run`.
- `TestMain` is located in a file named `testhelper_test.go`.
One limitation is that the `_test` package is scanned in a separate pass
from the primary package, preventing us from validating that either the
primary package or its `_test` package has defined `TestMain`. By
default each analysis pass has no knowledge of what other packages have
or will be scanned.
To avoid accidentally requiring `TestMain` to be defined twice, we skip
linting any package with a name ending with `_test`. However, this
potentially leads to coverage gaps if all tests are in the `_test`
package. We would pass the primary package as it has no tests, and then
skip checking the test package based on its name, missing that it did
not execute `TestMain`.
A future iteration of this linter should use `Facts` to pass information
on package state between passes, but this first implementation gets us
90% of the value.
Diffstat (limited to 'tools/golangci-lint/gitaly')
7 files changed, 197 insertions, 0 deletions
diff --git a/tools/golangci-lint/gitaly/lint.go b/tools/golangci-lint/gitaly/lint.go index 0d49db4ed..93e4da5ac 100644 --- a/tools/golangci-lint/gitaly/lint.go +++ b/tools/golangci-lint/gitaly/lint.go @@ -26,6 +26,10 @@ func New(conf any) ([]*analysis.Analyzer, error) { unavailableCodeAnalyzerName, "included-functions", )}), + newTesthelperRunAnalyzer(&testhelperRunAnalyzerSettings{IncludedFunctions: configStringSlicesAt( + testhelperRunAnalyzerName, + "included-functions", + )}), newTestParamsOrder(), }, nil } diff --git a/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_exec_testmain/testhelper_test.go b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_exec_testmain/testhelper_test.go new file mode 100644 index 000000000..94eb334f0 --- /dev/null +++ b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_exec_testmain/testhelper_test.go @@ -0,0 +1,8 @@ +package testhelper_run_no_exec_testmain + +import ( + "testing" +) + +func TestMain(m *testing.M) { // want "testhelper.Run not called in TestMain" +} diff --git a/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_testmain/no_testmain.go b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_testmain/no_testmain.go new file mode 100644 index 000000000..364b9f101 --- /dev/null +++ b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_testmain/no_testmain.go @@ -0,0 +1,6 @@ +package testhelper_run_no_testmain // want "no TestMain in package testhelper_run_no_testmain" + +import "testing" + +func TestMe(t *testing.T) { +} diff --git a/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_tests/no_tests.go b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_tests/no_tests.go new file mode 100644 index 000000000..a5ad77c85 --- /dev/null +++ b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_no_tests/no_tests.go @@ -0,0 +1,4 @@ +package testhelper_run_no_tests + +func hello() { // OK, no tests in package. +} diff --git a/tools/golangci-lint/gitaly/testdata/src/testhelper_run_not_testhelper/not_testhelper.go b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_not_testhelper/not_testhelper.go new file mode 100644 index 000000000..28afec330 --- /dev/null +++ b/tools/golangci-lint/gitaly/testdata/src/testhelper_run_not_testhelper/not_testhelper.go @@ -0,0 +1,9 @@ +package testhelper_run_not_testhelper + +import "testing" + +func Run(m *testing.M) {} + +func TestMain(m *testing.M) { // want "TestMain should be placed in file 'testhelper_test.go'" + Run(m) +} diff --git a/tools/golangci-lint/gitaly/testhelper_run.go b/tools/golangci-lint/gitaly/testhelper_run.go new file mode 100644 index 000000000..aa9226c02 --- /dev/null +++ b/tools/golangci-lint/gitaly/testhelper_run.go @@ -0,0 +1,136 @@ +package main + +import ( + "fmt" + "go/ast" + "go/types" + "path/filepath" + "regexp" + "strings" + + "golang.org/x/tools/go/analysis" +) + +const testhelperRunAnalyzerName = "testhelper_run" + +type testhelperRunAnalyzerSettings struct { + IncludedFunctions []string `mapstructure:"included-functions"` +} + +var toolPrefixPattern = regexp.MustCompile(`^gitlab.com/gitlab-org/gitaly(/v\d{2})?/tools`) + +// newTesthelperRunAnalyzer returns an analyzer to detect if a package that has tests does +// not contain a `TestMain()` function that executes `testhelper.Run()`. +// For more information: +// https://gitlab.com/gitlab-org/gitaly/-/blob/master/STYLE.md?ref_type=heads#common-setup +func newTesthelperRunAnalyzer(settings *testhelperRunAnalyzerSettings) *analysis.Analyzer { + return &analysis.Analyzer{ + Name: testhelperRunAnalyzerName, + Doc: `TestMain must be present and call testhelper.Run()`, + Run: runTesthelperRunAnalyzer(settings.IncludedFunctions), + } +} + +func runTesthelperRunAnalyzer(rules []string) func(*analysis.Pass) (interface{}, error) { + return func(pass *analysis.Pass) (interface{}, error) { + var hasTestMain, hasTests bool + + // Blackbox test packages ending with `_test` are considered to be + // part of the primary package for compilation, but are scanned in a + // separate pass by the analyzer. The primary and test packages cannot + // both define `TestMain`. Only require `TestMain` in the primary package. + if strings.HasSuffix(pass.Pkg.Name(), "_test") { + return nil, nil + } + + // Don't lint tools, they can't import `testhelper`. + if toolPrefixPattern.MatchString(pass.Pkg.Path()) { + return nil, nil + } + + for _, file := range pass.Files { + if hasTestMain { + break + } + + ast.Inspect(file, func(node ast.Node) bool { + if decl, ok := node.(*ast.FuncDecl); ok { + declName := decl.Name.Name + + if declName == "TestMain" { + hasTestMain = true + + analyzeTestMain(pass, decl, rules) + analyzeFilename(pass, file, decl) + } + + // Actual tests must start with `Test`, helpers could take a `testing.TB`. + if strings.HasPrefix(declName, "Test") { + params := decl.Type.Params + for _, field := range params.List { + fieldType := pass.TypesInfo.TypeOf(field.Type) + + // Do we have any tests in this package? + if types.Implements(fieldType, testingTB) { + hasTests = true + } + } + } + } + return true + }) + } + + // If we have tests but there's no `TestMain`, report. + if hasTests && !hasTestMain { + // We don't have a specific location for this failure, so use the location of the package name + // in its first file and provide the name in the error text. This list is sorted lexically by + // filename, so the location of `nolint` directives may not be stable when new files are added. + pass.Report(analysis.Diagnostic{ + Pos: pass.Files[0].Name.Pos(), + End: pass.Files[0].Name.End(), + Message: fmt.Sprintf("no TestMain in package %v", pass.Pkg.Path()), + SuggestedFixes: nil, + }) + } + + return nil, nil + } +} + +func analyzeFilename(pass *analysis.Pass, file *ast.File, decl *ast.FuncDecl) { + fullpath := pass.Fset.File(file.Pos()).Name() + filename := filepath.Base(fullpath) + + if filename != "testhelper_test.go" { + pass.Report(analysis.Diagnostic{ + Pos: decl.Pos(), + End: decl.End(), + Message: "TestMain should be placed in file 'testhelper_test.go'", + SuggestedFixes: nil, + }) + } +} + +func analyzeTestMain(pass *analysis.Pass, decl *ast.FuncDecl, rules []string) { + matcher := NewMatcher(pass) + var hasRun bool + + ast.Inspect(decl, func(node ast.Node) bool { + if call, ok := node.(*ast.CallExpr); ok { + if matcher.MatchFunction(call, rules) { + hasRun = true + } + } + return true + }) + + if !hasRun { + pass.Report(analysis.Diagnostic{ + Pos: decl.Pos(), + End: decl.End(), + Message: "testhelper.Run not called in TestMain", + SuggestedFixes: nil, + }) + } +} diff --git a/tools/golangci-lint/gitaly/testhelper_run_test.go b/tools/golangci-lint/gitaly/testhelper_run_test.go new file mode 100644 index 000000000..e557d5287 --- /dev/null +++ b/tools/golangci-lint/gitaly/testhelper_run_test.go @@ -0,0 +1,30 @@ +package main + +import ( + "os" + "path/filepath" + "testing" + + "golang.org/x/tools/go/analysis/analysistest" +) + +func TestTesthelperRun(t *testing.T) { + wd, err := os.Getwd() + if err != nil { + t.Fatalf("Failed to get wd: %s", err) + } + + testdata := filepath.Join(wd, "testdata") + analyzer := newTesthelperRunAnalyzer(&testhelperRunAnalyzerSettings{IncludedFunctions: []string{ + "testhelper_run_not_testhelper.Run", + }}) + analysistest.Run( + t, + testdata, + analyzer, + "testhelper_run_no_tests", + "testhelper_run_no_testmain", + "testhelper_run_no_exec_testmain", + "testhelper_run_not_testhelper", + ) +} |