Enhance missing expect assertions call rule to report error when expe…

…ct.assertions() call is present but the argument provided is not a number.
jest-community · Jan 1, 2018 · e3203d0 · e3203d0
1 parent 1989ffc
commit e3203d0
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Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/rules/__tests__/missing_expect_assertions_call_test.js b/rules/__tests__/missing_expect_assertions_call_test.js
@@ -41,6 +41,14 @@ ruleTester.run(
           },
         ],
       },
+      {
+        code: 'it("it1", function() {expect.assertions();})',
+        errors: [
+          {
+            message: expectedMsg,
+          },
+        ],
+      },
     ],
 
     valid: [

diff --git a/rules/missing_expect_assertions_call.js b/rules/missing_expect_assertions_call.js
@@ -3,13 +3,22 @@
 const ruleMsg =
   'Every test should have expect.assertions({number of assertions}) as first expression';
 
+const isValidArgument = expression => {
+  try {
+    return Number.isInteger(expression.arguments[0].value);
+  } catch (e) {
+    return false;
+  }
+};
+
 const isExpectAssertionsCall = expression => {
   try {
     return (
       expression.type == 'CallExpression' &&
       expression.callee.type == 'MemberExpression' &&
       expression.callee.object.name == 'expect' &&
-      expression.callee.property.name == 'assertions'
+      expression.callee.property.name == 'assertions' &&
+      isValidArgument(expression)
     );
   } catch (e) {
     return false;