dvc: add trailing newline in --show-md (#4124)

To finalize md table.

Fixes #4123

dvc/utils/diff.py

@@ -91,7 +91,7 @@ def table(header, rows, markdown=False):
     if not rows and not markdown:
         return ""
 
-    return tabulate(
+    ret = tabulate(
         rows,
         header,
         tablefmt="github" if markdown else "plain",
@@ -100,6 +100,12 @@ def table(header, rows, markdown=False):
         missingval="None",
     )
 
+    if markdown:
+        # NOTE: md table is incomplete without the trailing newline
+        ret += "\n"
+
+    return ret
+
 
 def format_dict(d):
     ret = {}

tests/unit/command/test_diff.py

@@ -114,7 +114,7 @@ def test_no_changes(mocker, caplog):
 
 
 def test_show_md_empty():
-    assert _show_md({}) == ("| Status   | Path   |\n" "|----------|--------|")
+    assert _show_md({}) == ("| Status   | Path   |\n|----------|--------|\n")
 
 
 def test_show_md():
@@ -138,5 +138,5 @@ def test_show_md():
         "| deleted  | data{sep}bar |\n"
         "| deleted  | data{sep}foo |\n"
         "| deleted  | zoo      |\n"
-        "| modified | file     |"
+        "| modified | file     |\n"
     ).format(sep=os.path.sep)

tests/unit/command/test_metrics.py

@@ -171,7 +171,8 @@ def test_metrics_diff_markdown_empty():
     assert _show_diff({}, markdown=True) == textwrap.dedent(
         """\
         | Path   | Metric   | Value   | Change   |
-        |--------|----------|---------|----------|"""
+        |--------|----------|---------|----------|
+        """
     )
 
 
@@ -191,7 +192,8 @@ def test_metrics_diff_markdown():
         |--------------|----------|---------|--------------------|
         | metrics.yaml | a.b.c    | 2       | 1                  |
         | metrics.yaml | a.d.e    | 4       | 1                  |
-        | metrics.yaml | x.b      | 6       | diff not supported |"""
+        | metrics.yaml | x.b      | 6       | diff not supported |
+        """
     )
 
 

tests/unit/command/test_params.py

@@ -129,7 +129,8 @@ def test_params_diff_markdown_empty():
     assert _show_diff({}, markdown=True) == textwrap.dedent(
         """\
         | Path   | Param   | Old   | New   |
-        |--------|---------|-------|-------|"""
+        |--------|---------|-------|-------|
+        """
     )
 
 
@@ -149,7 +150,8 @@ def test_params_diff_markdown():
         |-------------|---------|-------|-------|
         | params.yaml | a.b.c   | 1     | None  |
         | params.yaml | a.d.e   | None  | 4     |
-        | params.yaml | x.b     | 5     | 6     |"""
+        | params.yaml | x.b     | 5     | 6     |
+        """
     )