initial commit: ifinit and boolnames

boolnames/analyzer.go

@@ -0,0 +1,119 @@
+package boolnames
+
+import (
+	"fmt"
+	"go/ast"
+	"go/types"
+	"slices"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/inspect"
+	"golang.org/x/tools/go/ast/inspector"
+)
+
+var defaultBoolNamePrefixes = []string{"is", "has", "can", "was"}
+
+var Analyzer = NewAnalyzer(Settings{})
+
+func NewAnalyzer(settings Settings) *analysis.Analyzer {
+	if len(settings.AllowedPrefixes) == 0 {
+		settings.AllowedPrefixes = defaultBoolNamePrefixes
+	}
+	return &analysis.Analyzer{
+		Name:     "boolnames",
+		Doc:      `checks that boolean values and functions use appropriate names`,
+		Requires: []*analysis.Analyzer{inspect.Analyzer},
+		Run: func(pass *analysis.Pass) (any, error) {
+			result, ok := pass.ResultOf[inspect.Analyzer]
+			if !ok {
+				return nil, fmt.Errorf("inspect analyzer result is unavailable")
+			}
+
+			insp, ok := result.(*inspector.Inspector)
+			if !ok {
+				return nil, fmt.Errorf("inspect analyzer returned %T, want *inspector.Inspector", result)
+			}
+
+			insp.Preorder([]ast.Node{(*ast.Ident)(nil)}, func(n ast.Node) {
+				ident, ok := n.(*ast.Ident)
+				if !ok {
+					return
+				}
+				obj := pass.TypesInfo.Defs[ident]
+				if obj == nil || ident.Name == "_" {
+					return
+				}
+
+				switch obj.(type) {
+				case *types.Var, *types.Const, *types.Func:
+				default:
+					return
+				}
+
+				if !hasBoolType(obj.Type()) {
+					return
+				}
+
+				if settings.IsAcceptableBoolName(ident.Name) {
+					return
+				}
+
+				pass.Reportf(ident.Pos(),
+					"boolean name %q must start with %s",
+					ident.Name,
+					strings.Join(settings.AllowedPrefixes, ", "),
+				)
+			})
+
+			return nil, nil
+		},
+	}
+}
+
+func hasBoolType(t types.Type) bool {
+	isBool := func(t types.Type) bool {
+		basic, ok := types.Unalias(t).Underlying().(*types.Basic)
+		if !ok {
+			return false
+		}
+
+		return basic.Kind() == types.Bool || basic.Kind() == types.UntypedBool
+	}
+	if isBool(t) {
+		return true
+	}
+
+	sig, ok := types.Unalias(t).Underlying().(*types.Signature)
+	if !ok {
+		return false
+	}
+
+	results := sig.Results()
+	return results.Len() == 1 && isBool(results.At(0).Type())
+}
+
+func (settings Settings) IsAcceptableBoolName(s string) bool {
+	if slices.Contains(settings.Whitelist, s) {
+		return true
+	}
+
+	for _, pfix := range settings.AllowedPrefixes {
+		if pfix == "" || len(s) <= len(pfix) || s[1:len(pfix)] != pfix[1:] {
+			continue
+		}
+
+		first := s[0]
+		if first != pfix[0] && first != pfix[0]-'a'+'A' {
+			continue
+		}
+
+		sfix := s[len(pfix):]
+		r, _ := utf8.DecodeRuneInString(sfix)
+		return unicode.IsUpper(r)
+	}
+
+	return false
+}