Allow use of "as Type" syntax for type assertions in test code.

.eslintrc.js

@@ -124,7 +124,7 @@ module.exports = {
  // Require class properties and methods to explicitly use accessibility modifiers (public, private, protected)
  '@typescript-eslint/explicit-member-accessibility': 'error',
 
- // Forbids an object literal to appear in a type assertion expression unless its used as a parameter. This
+ // Forbids an object literal to appear in a type assertion expression unless its used as a parameter (we violate this rule for test code, to allow for looser property matching for objects - more in the test-specific rules section below). This
  // allows the typechecker to perform validation on the value as an assignment, instead of allowing the type
  // assertion to always win.
  // Requires use of `as Type` instead of `<Type>` for type assertion. Consistency.
@@ -267,6 +267,13 @@ module.exports = {
  // See https://github.com/slackapi/bolt-js/pull/1012#pullrequestreview-711232738
  // for a case of arrow-vs-function syntax coming up for the team
  'prefer-arrow-callback': 'off',
+
+ // Unlike non-test-code, where we requireq use of `as Type` instead of `<Type>` for type assertion, in test code using the looser `as Type` syntax leads to easier test writing, since only required properties must be adhered to using the `as Type` syntax.
+ '@typescript-eslint/consistent-type-assertions': ['error', {
+ assertionStyle: 'as',
+ objectLiteralTypeAssertions: 'allow',
+ }],
+
  },
  },
  ],