var-spacing: fix multiline nested JSON false positive (#1672)

* E206: Increase testing accuracy

VariableHasSpacesRule testing was limited to ensuring that the number of
error was matching an expected number. This could have potential
limitation where for example a commit prevents an real linting error
from being raised and in the same time raises an invalid one.

This commit aims at improving this rule's testing by ensuring that
errors are raised only on a controlled set of lines.

Related to: #1671

* E206: Add testing for false positive nested JSON

This commit adds 4 new tasks in example playbook used for
VariableHasSpacesRule testing.

One of these rule is a nested multiline JSON object which has its
opening and closing brackets spanned on different lines. And this rule
raises false positive error.

Related to #1671

* E206: Fix multiline nested JSON false positive

When using a nested JSON object spanned on multiple lines in a Jinja2
context ansible-lint raises a false positive E206 error.

This commit extends the regex in charge of excluding false positive JSON
objects so that it handles multiline matching.

Fixes #1671

Co-authored-by: Sorin Sbarnea <ssbarnea@redhat.com>

examples/playbooks/var-spacing.yml

@@ -1,4 +1,4 @@
-# Should raise var-spacing at lines 25, 28, 31
+# Should raise var-spacing at tasks line 23, 26, 29, 54, 65
 - hosts: all
   tasks:
     - name: good variable format
@@ -46,3 +46,25 @@
             case2 }}
       debug:
         var: cases
+
+    - name: Valid single line nested JSON false positive
+      debug:
+        msg: "{{ {'dummy_2': {'nested_dummy_1': 'value_1', 'nested_dummy_2': value_2}} | combine(dummy_1) }}"
+
+    - name: Invalid single line nested JSON
+      debug:
+        msg: "{{ {'dummy_2': {'nested_dummy_1': 'value_1', 'nested_dummy_2': value_2}} | combine(dummy_1)}}"
+
+    - name: Valid multiline nested JSON false positive
+      debug:
+        msg: >-
+          {{ {'dummy_2': {'nested_dummy_1': value_1,
+                          'nested_dummy_2': value_2}} |
+          combine(dummy_1) }}
+
+    - name: Invalid multiline nested JSON
+      debug:
+        msg: >-
+          {{ {'dummy_2': {'nested_dummy_1': value_1,
+                          'nested_dummy_2': value_2}} |
+          combine(dummy_1)}}

src/ansiblelint/rules/VariableHasSpacesRule.py

@@ -3,7 +3,7 @@
 
 import re
 import sys
-from typing import Any, Dict, Optional, Union
+from typing import Any, Dict, List, Optional, Union
 
 from ansiblelint.file_utils import Lintable
 from ansiblelint.rules import AnsibleLintRule
@@ -20,7 +20,7 @@ class VariableHasSpacesRule(AnsibleLintRule):
     version_added = 'v4.0.0'
 
     bracket_regex = re.compile(r"{{[^{\n' -]|[^ '\n}-]}}", re.MULTILINE | re.DOTALL)
-    exclude_json_re = re.compile(r"[^{]{'\w+': ?[^{]{.*?}}")
+    exclude_json_re = re.compile(r"[^{]{'\w+': ?[^{]{.*?}}", re.MULTILINE | re.DOTALL)
 
     def matchtask(
         self, task: Dict[str, Any], file: Optional[Lintable] = None
@@ -35,15 +35,36 @@ def matchtask(
 
 if 'pytest' in sys.modules:
 
-    from ansiblelint.rules import RulesCollection
-    from ansiblelint.runner import Runner
+    import pytest
 
-    def test_var_spacing() -> None:
-        """Verify rule."""
+    from ansiblelint.rules import RulesCollection  # pylint: disable=ungrouped-imports
+    from ansiblelint.runner import Runner  # pylint: disable=ungrouped-imports
+
+    @pytest.fixture
+    def error_expected_lines() -> List[int]:
+        """Return list of expected error lines."""
+        return [23, 26, 29, 54, 65]
+
+    @pytest.fixture
+    def test_playbook() -> str:
+        """Return test cases playbook path."""
+        return "examples/playbooks/var-spacing.yml"
+
+    @pytest.fixture
+    def lint_error_lines(test_playbook: str) -> List[int]:
+        """Get VarHasSpacesRules linting results on test_playbook."""
         collection = RulesCollection()
         collection.register(VariableHasSpacesRule())
-
-        lintable = Lintable("examples/playbooks/var-spacing.yml")
+        lintable = Lintable(test_playbook)
         results = Runner(lintable, rules=collection).run()
+        return list(map(lambda item: item.linenumber, results))
 
-        assert len(results) == 3
+    def test_var_spacing(
+        error_expected_lines: List[int], lint_error_lines: List[int]
+    ) -> None:
+        """Ensure that expected error lines are matching found linting error lines."""
+        # list unexpected error lines or non-matching error lines
+        error_lines_difference = list(
+            set(error_expected_lines).symmetric_difference(set(lint_error_lines))
+        )
+        assert len(error_lines_difference) == 0