storj/scripts/check-errs.go
2019-08-27 19:07:12 +03:00

84 lines
2.0 KiB
Go

// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.
// +build ignore
package main
import (
"go/ast"
"go/token"
"golang.org/x/tools/go/analysis"
"golang.org/x/tools/go/analysis/passes/inspect"
"golang.org/x/tools/go/analysis/singlechecker"
"golang.org/x/tools/go/ast/inspector"
"golang.org/x/tools/go/types/typeutil"
)
func main() { singlechecker.Main(Analyzer) }
var Analyzer = &analysis.Analyzer{
Name: "errs",
Doc: "check for proper usage of errs package",
Run: run,
Requires: []*analysis.Analyzer{
inspect.Analyzer,
},
FactTypes: []analysis.Fact{},
}
func run(pass *analysis.Pass) (interface{}, error) {
inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
nodeFilter := []ast.Node{
(*ast.CallExpr)(nil),
}
inspect.Preorder(nodeFilter, func(n ast.Node) {
call := n.(*ast.CallExpr)
fn := typeutil.StaticCallee(pass.TypesInfo, call)
if fn == nil {
return // not a static call
}
switch fn.FullName() {
case "github.com/zeebo/errs.Combine":
if len(call.Args) == 0 {
pass.Reportf(call.Lparen, "errs.Combine() can be simplified to nil")
}
if len(call.Args) == 1 && call.Ellipsis == token.NoPos {
pass.Reportf(call.Lparen, "errs.Combine(x) can be simplified to x")
}
case "(*github.com/zeebo/errs.Class).New":
if len(call.Args) == 0 {
return
}
// Disallow things like Error.New(err.Error())
switch arg := call.Args[0].(type) {
case *ast.BasicLit: // allow string constants
case *ast.Ident: // allow string variables
default:
// allow "alpha" + "beta" + "gamma"
if IsConcatString(arg) {
return
}
pass.Reportf(call.Lparen, "(*errs.Class).New with non-obvious format string")
}
}
})
return nil, nil
}
func IsConcatString(arg ast.Expr) bool {
switch arg := arg.(type) {
case *ast.BasicLit:
return arg.Kind == token.STRING
case *ast.BinaryExpr:
return arg.Op == token.ADD && IsConcatString(arg.X) && IsConcatString(arg.Y)
default:
return false
}
}