121 lines
2.6 KiB
Go
121 lines
2.6 KiB
Go
package rule
|
|
|
|
import (
|
|
"fmt"
|
|
"go/ast"
|
|
"go/types"
|
|
|
|
"github.com/mgechev/revive/lint"
|
|
)
|
|
|
|
// UnhandledErrorRule lints given else constructs.
|
|
type UnhandledErrorRule struct{}
|
|
|
|
type ignoreListType map[string]struct{}
|
|
|
|
// Apply applies the rule to given file.
|
|
func (r *UnhandledErrorRule) Apply(file *lint.File, args lint.Arguments) []lint.Failure {
|
|
var failures []lint.Failure
|
|
|
|
ignoreList := make(ignoreListType, len(args))
|
|
|
|
for _, arg := range args {
|
|
argStr, ok := arg.(string)
|
|
if !ok {
|
|
panic(fmt.Sprintf("Invalid argument to the unhandled-error rule. Expecting a string, got %T", arg))
|
|
}
|
|
|
|
ignoreList[argStr] = struct{}{}
|
|
}
|
|
|
|
walker := &lintUnhandledErrors{
|
|
ignoreList: ignoreList,
|
|
pkg: file.Pkg,
|
|
onFailure: func(failure lint.Failure) {
|
|
failures = append(failures, failure)
|
|
},
|
|
}
|
|
|
|
file.Pkg.TypeCheck()
|
|
ast.Walk(walker, file.AST)
|
|
|
|
return failures
|
|
}
|
|
|
|
// Name returns the rule name.
|
|
func (r *UnhandledErrorRule) Name() string {
|
|
return "unhandled-error"
|
|
}
|
|
|
|
type lintUnhandledErrors struct {
|
|
ignoreList ignoreListType
|
|
pkg *lint.Package
|
|
onFailure func(lint.Failure)
|
|
}
|
|
|
|
// Visit looks for statements that are function calls.
|
|
// If the called function returns a value of type error a failure will be created.
|
|
func (w *lintUnhandledErrors) Visit(node ast.Node) ast.Visitor {
|
|
switch n := node.(type) {
|
|
case *ast.ExprStmt:
|
|
fCall, ok := n.X.(*ast.CallExpr)
|
|
if !ok {
|
|
return nil // not a function call
|
|
}
|
|
|
|
funcType := w.pkg.TypeOf(fCall)
|
|
if funcType == nil {
|
|
return nil // skip, type info not available
|
|
}
|
|
|
|
switch t := funcType.(type) {
|
|
case *types.Named:
|
|
if !w.isTypeError(t) {
|
|
return nil // func call does not return an error
|
|
}
|
|
|
|
w.addFailure(fCall)
|
|
default:
|
|
retTypes, ok := funcType.Underlying().(*types.Tuple)
|
|
if !ok {
|
|
return nil // skip, unable to retrieve return type of the called function
|
|
}
|
|
|
|
if w.returnsAnError(retTypes) {
|
|
w.addFailure(fCall)
|
|
}
|
|
}
|
|
}
|
|
return w
|
|
}
|
|
|
|
func (w *lintUnhandledErrors) addFailure(n *ast.CallExpr) {
|
|
funcName := gofmt(n.Fun)
|
|
if _, mustIgnore := w.ignoreList[funcName]; mustIgnore {
|
|
return
|
|
}
|
|
|
|
w.onFailure(lint.Failure{
|
|
Category: "bad practice",
|
|
Confidence: 1,
|
|
Node: n,
|
|
Failure: fmt.Sprintf("Unhandled error in call to function %v", funcName),
|
|
})
|
|
}
|
|
|
|
func (*lintUnhandledErrors) isTypeError(t *types.Named) bool {
|
|
const errorTypeName = "_.error"
|
|
|
|
return t.Obj().Id() == errorTypeName
|
|
}
|
|
|
|
func (w *lintUnhandledErrors) returnsAnError(tt *types.Tuple) bool {
|
|
for i := 0; i < tt.Len(); i++ {
|
|
nt, ok := tt.At(i).Type().(*types.Named)
|
|
if ok && w.isTypeError(nt) {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|