import-checker: use testparseutil.embedded() to centralize detection logic
This patch fixes issues of embedded() in import-checker.py below, too.
- overlook (or mis-detect) the end of inline script in doctest style
- overlook inline script in doctest style at the end of file
(and ignore invalid un-closed heredoc at the end of file, too)
- overlook code fragment in styles below
- "python <<EOF" (heredoc should be "cat > file <<EOF" style)
- "cat > foobar.py << ANYLIMIT" (limit mark should be "EOF")
- "cat << EOF > foobar.py" (filename should be placed before limit mark)
- "cat >> foobar.py << EOF" (appending is ignored)
To run the tests, do:
cd tests/
python run-tests.py
See https://mercurial-scm.org/wiki/WritingTests for
more information on writing tests.