Optional ESLint config

The @kensio/smartass package also exports an optional ESLint flat config that discourages less specific assertion usage. For example:

assertIdentical(foo.length, 2);
// suggested improvement:
assertArrayLength(foo, 2);

You can use this in your ESLint config like this:

import { defineConfig } from "eslint/config";
import tseslint from "typescript-eslint";

import { smartassPreferSpecificAssertions } from "@kensio/smartass/eslint";

export default defineConfig(
  ...tseslint.configs.recommended,
  ...smartassPreferSpecificAssertions,
);

Some more examples of the replacements that the ESLint rules will suggest:

• assertIdentical(value, true) → assertTrue(value)
• assertIdentical(value, false) → assertFalse(value)
• assertIdentical(value, undefined) → assertUndefined(value)
• assertTrue(value != null) → assertNonNullable(value)
• assertIdentical(typeof value, "string") → assertTypeString(value)
• assertIdentical(value instanceof MyClass, true) → assertInstanceOf(value, MyClass)
• assertIdentical("key" in object, true) → assertObjectHasProperty(object, "key")
• assertIdentical(value.length, expected) → assertArrayLength() etc.
• assertIdentical(value.size, expected) → assertSetSize() etc.
• assertTrue(array.length > 0) → assertArrayNotEmpty(array)
• assertTrue(value.includes(expected)) → assertStringIncludes() etc.
• assertTrue(value.startsWith(prefix)) → assertStringStartsWith(value, prefix)
• assertTrue(value.endsWith(suffix)) → assertStringEndsWith(value, suffix)
• assertTrue(stats.isDirectory()) → assertDirectoryExists() etc.