Added tests and cleaned find_executables

Author: prmtl

pydot_ng/__init__.py

@@ -417,40 +417,47 @@ def __find_executables(path):
     """
 
     success = False
-    progs = {'dot': '', 'twopi': '', 'neato': '', 'circo': '', 'fdp': '',
-             'sfdp': ''}
+    progs = {
+        "dot": "",
+        "twopi": "",
+        "neato": "",
+        "circo": "",
+        "fdp": "",
+        "sfdp": "",
+    }
 
     was_quoted = False
     path = path.strip()
     if path.startswith('"') and path.endswith('"'):
         path = path[1:-1]
         was_quoted = True
 
-    if os.path.isdir(path):
-        for prg in progs.keys():
-            if progs[prg]:
-                continue
+    if not os.path.isdir(path):
+        return None
 
-            if os.path.exists(os.path.join(path, prg)):
-                if was_quoted:
-                    progs[prg] = '"' + os.path.join(path, prg) + '"'
-                else:
-                    progs[prg] = os.path.join(path, prg)
+    for prg in progs:
+        if progs[prg]:
+            continue
 
-                success = True
+        prg_path = os.path.join(path, prg)
+        prg_exe_path = prg_path + ".exe"
 
-            elif os.path.exists(os.path.join(path, prg + '.exe')):
-                if was_quoted:
-                    progs[prg] = '"' + os.path.join(path, prg + '.exe') + '"'
-                else:
-                    progs[prg] = os.path.join(path, prg + '.exe')
+        if os.path.exists(prg_path):
+            if was_quoted:
+                prg_path = "\"{}\"".format(prg_path)
+            progs[prg] = prg_path
+            success = True
 
-                success = True
+        elif os.path.exists(prg_exe_path):
+            if was_quoted:
+                prg_exe_path = "\"{}\"".format(prg_exe_path)
+            progs[prg] = prg_exe_path
+            success = True
 
     if success:
         return progs
-    else:
-        return None
+
+    return None
 
 
 # The multi-platform version of this 'find_graphviz' function was

test/test_pydot.py

@@ -278,3 +278,58 @@ def test_dotparser_import_warning():
             del sys.modules["pydot_ng"]
             warnings.simplefilter("always")
             import pydot_ng  # noqa: F401
+
+
+def test_find_executables_fake_path():
+    assert pydot.__find_executables("/fake/path/") is None
+
+
+def test_find_executables_real_path_no_programs(tmpdir):
+    assert pydot.__find_executables(str(tmpdir)) is None
+
+
+def test_find_executables_path_needs_strip(tmpdir):
+    path = tmpdir.mkdir("subdir")
+    prog_path = str(path.join("dot"))
+
+    path_with_spaces = "    {}     ".format(path)
+
+    with open(prog_path, "w"):
+        progs = pydot.__find_executables(path_with_spaces)
+        assert progs["dot"] == prog_path
+        assert sorted(
+            ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
+        ) == sorted(progs)
+
+
+def test_find_executables_unix_and_exe_exists(tmpdir):
+    path = str(tmpdir)
+    prog_unix_path = str(tmpdir.join("dot"))
+    prog_exe_path = str(tmpdir.join("dot.exe"))
+
+    with open(prog_unix_path, "w"):
+        with open(prog_exe_path, "w"):
+            progs = pydot.__find_executables(path)
+            assert progs["dot"] == prog_unix_path
+            assert progs["dot"] != prog_exe_path
+
+
+@pytest.mark.parametrize("quoted", (True, False), ids=("quoted", "unqoted"))
+@pytest.mark.parametrize("extension", ("", ".exe"))
+@pytest.mark.parametrize(
+    "program", ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
+)
+def test_find_executables(tmpdir, program, extension, quoted):
+    path = tmpdir.mkdir("PYDOT is_da best!")
+    prog_path = str(path.join(program + extension))
+
+    with open(prog_path, "w"):
+        if quoted:
+            path = "\"{}\"".format(path)
+            prog_path = "\"{}\"".format(prog_path)
+
+        progs = pydot.__find_executables(str(path))
+        assert progs[program] == prog_path
+        assert sorted(
+            ("dot", "twopi", "neato", "circo", "fdp", "sfdp")
+        ) == sorted(progs)