test_intermediary_to_dot.py

import re
import sys
from multiprocessing import Process

import pytest
from pygraphviz import AGraph

from eralchemy.cst import DOT_GRAPH_BEGINNING
from eralchemy.main import _intermediary_to_dot
from tests.common import (
    child,
    child_id,
    child_parent_id,
    parent,
    parent_id,
    parent_name,
    relation,
)

GRAPH_LAYOUT = DOT_GRAPH_BEGINNING + "%s }"
column_re = re.compile(
    '\\<TR\\>\\<TD\\ ALIGN\\=\\"LEFT\\"\\>(.*)\\<\\/TD\\>\\<\\/TR\\>',
)
header_re = re.compile(
    '\\<TR\\>\\<TD\\>\\<B\\>\\<FONT\\ POINT\\-SIZE\\=\\"16\\"\\>(.*)'
    "\\<\\/FONT\\>\\<\\/B\\>\\<\\/TD\\>\\<\\/TR\\>",
)
column_inside = re.compile(
    "(?P<key_opening>.*)\\<FONT\\>(?P<name>.*)\\<\\/FONT\\>"
    "(?P<key_closing>.*)\\ <FONT\\>\\ \\[(?P<type>.*)\\]\\<\\/FONT\\>",
)


# This test needs fixing with move to graphviz
def assert_is_dot_format(dot):
    """Checks that the dot is usable by graphviz."""

    # We launch a process calling graphviz to render the dot. If the exit code is not 0 we assume that the syntax
    # wasn't good
    def run_graph(dot):
        """Runs graphviz to see if the syntax is good."""
        graph = AGraph()
        graph = graph.from_string(dot)
        extension = "png"
        graph.draw(path="output.png", prog="dot", format=extension)
        sys.exit(0)

    p = Process(target=run_graph, args=(dot,))
    p.start()
    p.join()
    assert p.exitcode == 0


def test_all_to_dot():
    tables = [child, parent]
    relations = [relation]
    output = _intermediary_to_dot(tables, relations)
    assert_is_dot_format(output)
    for element in relations + tables:
        assert element.to_dot() in output


@pytest.mark.parametrize(
    "title",
    ("Test Title", "häßlicher Titel!", "<div> -not.parsed_ </div>"),  # codespell:ignore
)
def test_all_to_dot_with_title(title):
    tables = [child, parent]
    relations = [relation]
    output = _intermediary_to_dot(tables, relations, title=title)
    assert_is_dot_format(output)
    for element in relations + tables:
        assert element.to_dot() in output


def assert_column_well_rendered_to_dot(col):
    col_no_table = column_re.match(col.to_dot()).groups()
    assert len(col_no_table) == 1
    col_parsed = column_inside.match(col_no_table[0])
    assert col_parsed.group("key_opening") == ("<u>" if col.is_key else "")
    assert col_parsed.group("name") == col.name
    assert col_parsed.group("key_closing") == ("</u>" if col.is_key else "")
    assert col_parsed.group("type") == col.type


def test_column_is_dot_format():
    assert_column_well_rendered_to_dot(parent_id)
    assert_column_well_rendered_to_dot(parent_name)
    assert_column_well_rendered_to_dot(child_id)
    assert_column_well_rendered_to_dot(child_parent_id)


def test_relation():
    relation_re = re.compile(
        '\\"(?P<l_name>.+)\\"\\ \\-\\-\\ \\"(?P<r_name>.+)\\"\\ '
        "\\[taillabel\\=\\<\\<FONT\\>(?P<l_card>.+)\\<\\/FONT\\>\\>"
        "\\,headlabel\\=\\<\\<FONT\\>(?P<r_card>.+)\\<\\/FONT\\>\\>\\]\\;",
    )
    dot = relation.to_dot()
    r = relation_re.match(dot)
    assert r.group("l_name") == "child"
    assert r.group("r_name") == "parent"
    assert r.group("l_card") == "0..N"
    assert r.group("r_card") == "{0,1}"


def assert_table_well_rendered_to_dot(table):
    matches = header_re.match(table.header_dot).groups()
    assert len(matches) == 1
    assert matches[0] == table.name
    table_dot = table.to_dot()
    for col in table.columns:
        assert col.to_dot() in table_dot


def test_table():
    assert_table_well_rendered_to_dot(child)
    assert_table_well_rendered_to_dot(parent)