Fix --format with paths containing colons (#484)

* Fix --format with paths containing colons

* Add test

Author: tkukushkin

diff_cover/diff_cover_tool.py

@@ -56,14 +56,11 @@
 def format_type(value):
     """
     Accepts:
-        --format html
-        --format json
-        --format json,html
-        --format html,json:path/to/file.json
+        --format html:path/to/file.html,json:path/to/file.json
 
         return: dict of strings to paths
     """
-    return dict((item.split(":") for item in value.split(",")) if value else {})
+    return dict((item.split(":", 1) for item in value.split(",")) if value else {})
 
 
 def parse_coverage_args(argv):

tests/test_diff_cover_tool.py

@@ -16,6 +16,18 @@ def test_parse_with_html_report():
     assert not arg_dict.get("ignore_unstaged")
 
 
+def test_report_path_with_colon():
+    argv = [
+        "reports/coverage.xml",
+        "--format",
+        "json:/this:path:should:work/without:breaking.json",
+    ]
+    arg_dict = parse_coverage_args(argv)
+    assert arg_dict.get("format") == {
+        "json": "/this:path:should:work/without:breaking.json"
+    }
+
+
 def test_parse_with_no_report():
     argv = ["reports/coverage.xml"]
     arg_dict = parse_coverage_args(argv)