Allow global config for rule testcases (sqlfluff#1580)

* FIx broken block comments in exasol

* Allow adding a global test config per testcase

* Respect config per testcase

* Allow adding a global test config per testcase

* Respect config per testcase

* add testcase

* make unittest description more meaningful

Co-authored-by: Alan Cruickshank <alanmcruickshank@gmail.com>
Co-authored-by: Barry Pollard <barry@tunetheweb.com>

src/sqlfluff/testing/rules.py

@@ -37,6 +37,11 @@ def load_test_cases(
         y = yaml.safe_load(raw)
 
         rule = y.pop("rule")
+        global_config = y.pop("configs", None)
+        if global_config:
+            for i in y:
+                if not ("configs" in y[i].keys()):
+                    y[i].update({"configs": global_config})
         ids.extend([rule + "_" + t for t in y])
         test_cases.extend([RuleTestCase(rule=rule, **v) for k, v in y.items()])
 

test/fixtures/rules/R001_global_config_test.yml

@@ -0,0 +1,16 @@
+rule: R001
+configs:
+    core:
+      dialect: exasol
+
+
+tc1:
+  pass_str: |
+    create table if not exists tab.xxx (col1 varchar(10))
+  configs:
+    core:
+      dialect: ansi
+
+tc2:
+  pass_str: |
+    create table tab.xxx (col1 varchar(10))

test/rules/yaml_test_cases_test.py

@@ -26,3 +26,15 @@ def test__rule_test_case(test_case, caplog):
             assert is_fix_compatible(
                 rule
             ), f'Rule {test_case.rule} returned fixes but does not specify "@document_fix_compatible".'
+
+
+def test__rule_test_global_config():
+    """Test global config in rule test cases."""
+    ids, test_cases = load_test_cases(
+        os.path.join("test/fixtures/rules/R001_global_config_test.yml")
+    )
+    assert len(test_cases) == 2
+    # tc1: overwrites global config
+    assert test_cases[0].configs["core"]["dialect"] == "ansi"
+    # tc2: global config is used
+    assert test_cases[1].configs["core"]["dialect"] == "exasol"