func fixImportCheck(body []byte, importPath string) ([]byte, error) {
fset := token.NewFileSet()
// todo: see if we can restrict the mode some more
f, err := parser.ParseFile(fset, "", body, parser.ParseComments)
if err != nil {
log.Fatal(err)
}
var after *ast.CommentGroup
var pos token.Pos = token.Pos(len(body))
for _, v := range f.Comments {
text := strings.TrimSpace(v.Text())
if v.Pos() > f.Package && v.Pos() < pos && strings.HasPrefix(text, "import") {
pos = v.Pos()
after = v
}
}
if after != nil && bytes.IndexByte(body[f.Package:pos], '\n') == -1 {
comment := fmt.Sprintf(`// import "%s"`, importPath)
buf := new(bytes.Buffer)
buf.Write(body[:after.Pos()-1])
buf.WriteString(comment)
buf.Write(body[after.End()-1:])
body = buf.Bytes()
}
return body, nil
}
// lintPackageComment checks package comments. It complains if
// there is no package comment, or if it is not of the right form.
// This has a notable false positive in that a package comment
// could rightfully appear in a different file of the same package,
// but that's not easy to fix since this linter is file-oriented.
func (f *file) lintPackageComment() {
if f.isTest() {
return
}
const ref = styleGuideBase + "#package-comments"
prefix := "Package " + f.f.Name.Name + " "
// Look for a detached package comment.
// First, scan for the last comment that occurs before the "package" keyword.
var lastCG *ast.CommentGroup
for _, cg := range f.f.Comments {
if cg.Pos() > f.f.Package {
// Gone past "package" keyword.
break
}
lastCG = cg
}
if lastCG != nil && strings.HasPrefix(lastCG.Text(), prefix) {
endPos := f.fset.Position(lastCG.End())
pkgPos := f.fset.Position(f.f.Package)
if endPos.Line+1 < pkgPos.Line {
// There isn't a great place to anchor this error;
// the start of the blank lines between the doc and the package statement
// is at least pointing at the location of the problem.
pos := token.Position{
Filename: endPos.Filename,
// Offset not set; it is non-trivial, and doesn't appear to be needed.
Line: endPos.Line + 1,
Column: 1,
}
f.pkg.errorfAt(pos, 0.9, link(ref), category("comments"), "package comment is detached; there should be no blank lines between it and the package statement")
return
}
}
if f.f.Doc == nil {
f.errorf(f.f, 0.2, link(ref), category("comments"), "should have a package comment, unless it's in another file for this package")
return
}
s := f.f.Doc.Text()
if ts := strings.TrimLeft(s, " \t"); ts != s {
f.errorf(f.f.Doc, 1, link(ref), category("comments"), "package comment should not have leading space")
s = ts
}
// Only non-main packages need to keep to this form.
if f.f.Name.Name != "main" && !strings.HasPrefix(s, prefix) {
f.errorf(f.f.Doc, 1, link(ref), category("comments"), `package comment should be of the form "%s..."`, prefix)
}
}