78 lines
1.8 KiB
Go
Vendored
78 lines
1.8 KiB
Go
Vendored
package rule
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import (
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"go/ast"
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"go/token"
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"github.com/mgechev/revive/lint"
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)
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// IndentErrorFlowRule lints given else constructs.
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type IndentErrorFlowRule struct{}
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// Apply applies the rule to given file.
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func (r *IndentErrorFlowRule) Apply(file *lint.File, _ lint.Arguments) []lint.Failure {
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var failures []lint.Failure
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onFailure := func(failure lint.Failure) {
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failures = append(failures, failure)
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}
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w := lintElse{make(map[*ast.IfStmt]bool), onFailure}
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ast.Walk(w, file.AST)
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return failures
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}
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// Name returns the rule name.
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func (r *IndentErrorFlowRule) Name() string {
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return "indent-error-flow"
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}
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type lintElse struct {
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ignore map[*ast.IfStmt]bool
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onFailure func(lint.Failure)
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}
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func (w lintElse) Visit(node ast.Node) ast.Visitor {
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ifStmt, ok := node.(*ast.IfStmt)
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if !ok || ifStmt.Else == nil {
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return w
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}
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if w.ignore[ifStmt] {
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if elseif, ok := ifStmt.Else.(*ast.IfStmt); ok {
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w.ignore[elseif] = true
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}
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return w
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}
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if elseif, ok := ifStmt.Else.(*ast.IfStmt); ok {
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w.ignore[elseif] = true
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return w
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}
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if _, ok := ifStmt.Else.(*ast.BlockStmt); !ok {
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// only care about elses without conditions
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return w
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}
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if len(ifStmt.Body.List) == 0 {
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return w
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}
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shortDecl := false // does the if statement have a ":=" initialization statement?
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if ifStmt.Init != nil {
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if as, ok := ifStmt.Init.(*ast.AssignStmt); ok && as.Tok == token.DEFINE {
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shortDecl = true
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}
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}
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lastStmt := ifStmt.Body.List[len(ifStmt.Body.List)-1]
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if _, ok := lastStmt.(*ast.ReturnStmt); ok {
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extra := ""
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if shortDecl {
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extra = " (move short variable declaration to its own line if necessary)"
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}
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w.onFailure(lint.Failure{
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Confidence: 1,
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Node: ifStmt.Else,
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Category: "indent",
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Failure: "if block ends with a return statement, so drop this else and outdent its block" + extra,
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})
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}
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return w
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}
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