test: added Violation tests

internal/checker/imports_test.go

@@ -72,7 +72,7 @@ func TestImports(t *testing.T) {
  ar, err := Txtar(t, fset, test.txtarPath)
 
  assert.Nil(t, err)
- assert.Len(t, len(ar), 1)
+ assert.Len(t, ar, 1)
 
  ins := inspector.New(ar)
  testImports := Load(fset, ins)

internal/checker/testing_test.go

@@ -8,9 +8,16 @@ import (
  "strings"
  "testing"
 
+ "github.com/stretchr/testify/assert"
  "golang.org/x/tools/txtar"
 )
 
+func ParseExprFrom(t *testing.T, fset *token.FileSet, src any) ast.Expr {
+ astExpr, err := parser.ParseExprFrom(fset, "a.go", src, parser.AllErrors)
+ assert.NoError(t, err)
+ return astExpr
+}
+
 func Txtar(t *testing.T, fset *token.FileSet, txtarPath string) (files []*ast.File, err error) {
  t.Helper()
 

internal/checker/violation_test.go

@@ -0,0 +1,107 @@
+package checker
+
+import (
+ "go/ast"
+ "go/token"
+ "testing"
+
+ "github.com/stretchr/testify/assert"
+)
+
+func TestViolation(t *testing.T) {
+ for i := range tests {
+ test := tests[i]
+ t.Run(test.Name, func(t *testing.T) {
+ fset := token.NewFileSet()
+ expr := ParseExprFrom(t, fset, test.Expression).(*ast.CallExpr)
+ args := make(map[int]ast.Expr, len(test.Args))
+ base := []byte(test.Base)
+
+ for n := range test.Args {
+ args[n] = ParseExprFrom(t, fset, test.Args[n])
+ }
+
+ v2 := test.Violation.With(base, expr, args)
+ assert.Equal(t, test.ExpectedSuggest, string(v2.suggest(fset)))
+ assert.Equal(t, test.Message, v2.Message())
+ })
+ }
+}
+
+var tests = []struct {
+ Name string
+ Violation Violation
+ Expression string
+ Base string
+ Args map[int]string
+ ExpectedSuggest string
+ Message string
+}{
+ {
+ Name: "alt Caller",
+ Violation: Violation{
+ Targets: Strings,
+ Type: Function,
+ Package: "regexp",
+ Caller: "MatchString",
+ Args: []int{1},
+ AltPackage: "foobar",
+ AltCaller: "Match",
+ },
+ Expression: `regexp.MatchString("[0-9]+", []bytes("foo"))`,
+ Args: map[int]string{1: `"foo"`},
+ Base: "regexp",
+ ExpectedSuggest: `regexp.Match("[0-9]+", "foo")`,
+ Message: `avoid allocations with foobar.Match`,
+ },
+ {
+ Name: "Has More Args Then WeNeed",
+ Violation: Violation{
+ Targets: Strings,
+ Type: Function,
+ Package: "regexp",
+ Caller: "MatchString",
+ Args: []int{1},
+ AltPackage: "foobar",
+ AltCaller: "Match",
+ },
+ Expression: `regexp.MatchString("[0-9]+", []bytes("foo"))`,
+ Args: map[int]string{1: `"foo"`, 2: `"foo"`, 3: `"foo"`, 4: `"foo"`},
+ Base: "regexp",
+ ExpectedSuggest: `regexp.Match("[0-9]+", "foo")`,
+ Message: `avoid allocations with foobar.Match`,
+ },
+ {
+ Name: "Regular Suggestion Work",
+ Violation: Violation{
+ Targets: Strings,
+ Type: Function,
+ Package: "regexp",
+ Caller: "MatchString",
+ Args: []int{1},
+ AltCaller: "Match",
+ },
+ Expression: `regexp.MatchString("[0-9]+", []bytes("foo"))`,
+ Args: map[int]string{1: `"foo"`},
+ Base: "regexp",
+ ExpectedSuggest: `regexp.Match("[0-9]+", "foo")`,
+ Message: `avoid allocations with regexp.Match`,
+ },
+ {
+ Name: "Methods",
+ Violation: Violation{
+ Targets: Strings,
+ Type: Method,
+ Package: "regexp",
+ Struct: "Regexp",
+ Caller: "MatchString",
+ Args: []int{1},
+ AltCaller: "Match",
+ },
+ Expression: `re.MatchString("[0-9]+", []bytes("foo"))`,
+ Args: map[int]string{1: `"foo"`},
+ Base: "re",
+ ExpectedSuggest: `re.Match("[0-9]+", "foo")`,
+ Message: `avoid allocations with (*regexp.Regexp).Match`,
+ },
+}