Improve customError testing (OpenZeppelin#4376)

test/helpers/customError.js

@@ -2,42 +2,43 @@ const { expect } = require('chai');
 
 /** Revert handler that supports custom errors. */
 async function expectRevertCustomError(promise, expectedErrorName, args) {
-  try {
-    await promise;
-    expect.fail("Expected promise to throw but it didn't");
-  } catch (revert) {
-    if (!Array.isArray(args)) {
-      expect.fail('Expected 3rd array parameter for error arguments');
-    }
-    // The revert message for custom errors looks like:
-    // VM Exception while processing transaction:
-    // reverted with custom error 'InvalidAccountNonce("0x70997970C51812dc3A010C7d01b50e0d17dc79C8", 0)'
-
-    // We trim out anything inside the single quotes as comma-separated values
-    const [, error] = revert.message.match(/'(.*)'/);
-
-    // Attempt to parse as an error
-    const match = error.match(/(?<name>\w+)\((?<args>.*)\)/);
-    if (!match) {
-      expect.fail(`Couldn't parse "${error}" as a custom error`);
-    }
-    // Extract the error name and parameters
-    const errorName = match.groups.name;
-    const argMatches = [...match.groups.args.matchAll(/-?\w+/g)];
-
-    // Assert error name
-    expect(errorName).to.be.equal(
-      expectedErrorName,
-      `Unexpected custom error name (with found args: [${argMatches.map(([a]) => a)}])`,
-    );
-
-    // Coerce to string for comparison since `arg` can be either a number or hex.
-    const sanitizedExpected = args.map(arg => arg.toString().toLowerCase());
-    const sanitizedActual = argMatches.map(([arg]) => arg.toString().toLowerCase());
-
-    // Assert argument equality
-    expect(sanitizedActual).to.have.members(sanitizedExpected, `Unexpected ${errorName} arguments`);
+  if (!Array.isArray(args)) {
+    expect.fail('Expected 3rd array parameter for error arguments');
   }
+
+  await promise.then(
+    () => expect.fail("Expected promise to throw but it didn't"),
+    ({ message }) => {
+      // The revert message for custom errors looks like:
+      // VM Exception while processing transaction:
+      // reverted with custom error 'InvalidAccountNonce("0x70997970C51812dc3A010C7d01b50e0d17dc79C8", 0)'
+
+      // We trim out anything inside the single quotes as comma-separated values
+      const [, error] = message.match(/'(.*)'/);
+
+      // Attempt to parse as an error
+      const match = error.match(/(?<name>\w+)\((?<args>.*)\)/);
+      if (!match) {
+        expect.fail(`Couldn't parse "${error}" as a custom error`);
+      }
+      // Extract the error name and parameters
+      const errorName = match.groups.name;
+      const argMatches = [...match.groups.args.matchAll(/-?\w+/g)];
+
+      // Assert error name
+      expect(errorName).to.be.equal(
+        expectedErrorName,
+        `Unexpected custom error name (with found args: [${argMatches.map(([a]) => a)}])`,
+      );
+
+      // Coerce to string for comparison since `arg` can be either a number or hex.
+      const sanitizedExpected = args.map(arg => arg.toString().toLowerCase());
+      const sanitizedActual = argMatches.map(([arg]) => arg.toString().toLowerCase());
+
+      // Assert argument equality
+      expect(sanitizedActual).to.have.members(sanitizedExpected, `Unexpected ${errorName} arguments`);
+    },
+  );
 }
 
 module.exports = {