Fixes undefined vars becoming null and erroring in conditions (#1356)

* fixed null vars

* fix: handle rules regex edge case

* Update tests/rules-regex.test.ts

* Update tests/rules-regex.test.ts

* fix

---------

Co-authored-by: ANGkeith <[email protected]>
Co-authored-by: Mads Jon Nielsen <[email protected]>

Author: 3 people

src/utils.ts

@@ -218,7 +218,7 @@ export class Utils {
                 default:
                     throw operator;
             }
-            return `.match(${rhs}${flags})${remainingTokens} ${_operator} null`;
+            return `.match(${rhs}${flags})${remainingTokens} ${_operator} null `;
         });
 
         // Scenario when RHS is surrounded by double-quotes
@@ -250,8 +250,10 @@ Refer to https://docs.gitlab.com/ee/ci/jobs/job_rules.html#unexpected-behavior-f
         });
 
         // Convert all null.match functions to false
-        evalStr = evalStr.replace(/null.match\(.+?\) != null/g, "false");
-        evalStr = evalStr.replace(/null.match\(.+?\) == null/g, "false");
+        evalStr = evalStr.replace(/null.match\(.+?\)\s*!=\s*null/g, "false");
+        evalStr = evalStr.replace(/null.match\(.+?\)\s*==\s*null/g, "false");
+
+        evalStr = evalStr.trim();
 
         let res;
         try {

tests/rules-regex.test.ts

@@ -72,6 +72,11 @@ const tests = [
         jsExpression: '"23".match(/1234/) != null',
         evalResult: false,
     },
+    {
+        rule: '$CI_COMMIT_BRANCH && $GITLAB_FEATURES =~ /\bdependency_scanning\b/ && $CI_GITLAB_FIPS_MODE == "true"',
+        jsExpression: 'null && false && null == "true"',
+        evalResult: false,
+    },
 ];
 /* eslint-enable @typescript-eslint/quotes */