test: refactor addons-napi/test_exception/test.js

* provide block scoping to prevent unintended side effects * remove confusing and unnecessary assertion message * use consisitent `actual, expected` argument order for assertions Backport-PR-URL: #19265 PR-URL: #18340 Reviewed-By: Colin Ihrig <[email protected]> Reviewed-By: Jon Moss <[email protected]> Reviewed-By: James M Snell <[email protected]>

Author: Trott

test/addons-napi/test_exception/test.js

@@ -4,49 +4,47 @@ const common = require('../../common');
 consttest_exception=require(`./build/${common.buildType}/test_exception`);
 constassert=require('assert');
 consttheError=newError('Some error');
-functionthrowTheError(){
-throwtheError;
+
+{
+constthrowTheError=()=>{throwtheError;};
+
+// Test that the native side successfully captures the exception
+letreturnedError=test_exception.returnException(throwTheError);
+assert.strictEqual(theError,returnedError);
+
+// Test that the native side passes the exception through
+assert.throws(
+()=>{test_exception.allowException(throwTheError);},
+(err)=>err===theError
+);
+
+// Test that the exception thrown above was marked as pending
+// before it was handled on the JS side
+assert.strictEqual(test_exception.wasPending(),true,
+'VM was marked as having an exception pending'+
+' when it was allowed through');
+
+// Test that the native side does not capture a non-existing exception
+returnedError=test_exception.returnException(common.mustCall());
+assert.strictEqual(returnedError,undefined,
+'Returned error should be undefined when no exception is'+
+` thrown, but ${returnedError} was passed`);
 }
-letcaughtError;
-
-// Test that the native side successfully captures the exception
-letreturnedError=test_exception.returnException(throwTheError);
-assert.strictEqual(theError,returnedError);
-
-// Test that the native side passes the exception through
-assert.throws(
-()=>{
-test_exception.allowException(throwTheError);
-},
-function(err){
-returnerr===theError;
-},
-'Thrown exception was allowed to pass through unhindered'
-);
-
-// Test that the exception thrown above was marked as pending
-// before it was handled on the JS side
-assert.strictEqual(test_exception.wasPending(),true,
-'VM was marked as having an exception pending'+
-' when it was allowed through');
-
-// Test that the native side does not capture a non-existing exception
-returnedError=test_exception.returnException(common.mustCall());
-assert.strictEqual(undefined,returnedError,
-'Returned error should be undefined when no exception is'+
-` thrown, but ${returnedError} was passed`);
-
-// Test that no exception appears that was not thrown by us
-try{
-test_exception.allowException(common.mustCall());
-}catch(anError){
-caughtError=anError;
+
+{
+// Test that no exception appears that was not thrown by us
+letcaughtError;
+try{
+test_exception.allowException(common.mustCall());
+}catch(anError){
+caughtError=anError;
+}
+assert.strictEqual(caughtError,undefined,
+'No exception originated on the native side, but'+
+` ${caughtError} was passed`);
+
+// Test that the exception state remains clear when no exception is thrown
+assert.strictEqual(test_exception.wasPending(),false,
+'VM was not marked as having an exception pending'+
+' when none was allowed through');
 }
-assert.strictEqual(undefined,caughtError,
-'No exception originated on the native side, but'+
-` ${caughtError} was passed`);
-
-// Test that the exception state remains clear when no exception is thrown
-assert.strictEqual(test_exception.wasPending(),false,
-'VM was not marked as having an exception pending'+
-' when none was allowed through');