copernicus find error

finderr.go

package main

import (
	"flag"
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"os"
	"path/filepath"
	"strings"
)

func checkerr(filename string) {
	fset := token.NewFileSet()
	f, err := parser.ParseFile(fset, filename, nil, 0)
	if err != nil {
		panic(err)
	}

	ast.Inspect(f, func(n ast.Node) bool {
		switch ifs := n.(type) {
		case *ast.IfStmt:
			for j := 0; j < len(ifs.Body.List); j++ {
				stmt := ifs.Body.List[j]
				es, ok := stmt.(*ast.ExprStmt)
				if !ok {
					continue
				}
				ce, ok := es.X.(*ast.CallExpr)
				if !ok {
					continue
				}

				se, ok := ce.Fun.(*ast.SelectorExpr)
				if !ok {
					continue
				}

				if ident, ok := se.X.(*ast.Ident); ok {
					if ident.Name == "log" && se.Sel.Name == "Error" {
						if j+1 >= len(ifs.Body.List) {
							fmt.Println(fset.Position(stmt.Pos()))
							break
						}

						stmt = ifs.Body.List[len(ifs.Body.List)-1]
						switch n := stmt.(type) {
						case *ast.ExprStmt:
							if ce, ok := n.X.(*ast.CallExpr); !ok {
								fmt.Println(fset.Position(stmt.Pos()))
							} else {
								if ident, ok := ce.Fun.(*ast.Ident); ok {
									if ident.Name == "panic" {
										break
									}
								}
							}
						case *ast.BranchStmt:
						case *ast.ReturnStmt:
						default:
							fmt.Println(fset.Position(stmt.Pos()))
						}
						break
					}
				}
			}
		}
		return true
	})
}

func visit(path string, f os.FileInfo, err error) error {
	if err != nil {
		fmt.Printf("prevent panic by handling failure accessing a path %q: %v\n", path, err)
		return err
	}

	if !strings.HasSuffix(path, "go") || strings.Contains(path, "vendor") {
		return nil
	}

	if f.IsDir() {
		return nil
	}

	checkerr(path)

	return nil
}

func main() {
	flag.Parse()
	root := flag.Arg(0)
	filepath.Walk(root, visit)
}