1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
package rule
import (
"go/ast"
"go/token"
"github.com/mgechev/revive/lint"
)
// IndentErrorFlowRule lints given else constructs.
type IndentErrorFlowRule struct{}
// Apply applies the rule to given file.
func (r *IndentErrorFlowRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
var failures []lint.Failure
onFailure := func(failure lint.Failure) {
failures = append(failures, failure)
}
w := lintElse{make(map[*ast.IfStmt]bool), onFailure}
ast.Walk(w, file.AST)
return failures
}
// Name returns the rule name.
func (r *IndentErrorFlowRule) Name() string {
return "indent-error-flow"
}
type lintElse struct {
ignore map[*ast.IfStmt]bool
onFailure func(lint.Failure)
}
func (w lintElse) Visit(node ast.Node) ast.Visitor {
ifStmt, ok := node.(*ast.IfStmt)
if !ok || ifStmt.Else == nil {
return w
}
if w.ignore[ifStmt] {
if elseif, ok := ifStmt.Else.(*ast.IfStmt); ok {
w.ignore[elseif] = true
}
return w
}
if elseif, ok := ifStmt.Else.(*ast.IfStmt); ok {
w.ignore[elseif] = true
return w
}
if _, ok := ifStmt.Else.(*ast.BlockStmt); !ok {
// only care about elses without conditions
return w
}
if len(ifStmt.Body.List) == 0 {
return w
}
shortDecl := false // does the if statement have a ":=" initialization statement?
if ifStmt.Init != nil {
if as, ok := ifStmt.Init.(*ast.AssignStmt); ok && as.Tok == token.DEFINE {
shortDecl = true
}
}
lastStmt := ifStmt.Body.List[len(ifStmt.Body.List)-1]
if _, ok := lastStmt.(*ast.ReturnStmt); ok {
extra := ""
if shortDecl {
extra = " (move short variable declaration to its own line if necessary)"
}
w.onFailure(lint.Failure{
Confidence: 1,
Node: ifStmt.Else,
Category: "indent",
Failure: "if block ends with a return statement, so drop this else and outdent its block" + extra,
})
}
return w
}
|
