type/no-unnecessary-boolean-literal-compare

Disallow unnecessary comparisons against boolean literals.

Applies to: Type information in Vue SFC scripts and templates, for the constructs shown below.

This rule reads type information from your TypeScript project (tsconfig.json), so the configuration sets typeAware: true. typeAware does not turn on opt-in rules by itself.

Bad

flag is already boolean, so comparing it with true adds no check.

<script setup lang="ts">
function isFlag(flag: boolean): boolean {
  return flag === true;
}
</script>

Good

Returning flag uses the boolean value directly.

<script setup lang="ts">
function isFlag(flag: boolean): boolean {
  return flag;
}
</script>

Configuration (Vite+)

import { defineConfig } from "@vizejs/vite-plugin/vite-plus";

export default defineConfig({}).withVue({
  linter: {
    "preset": "incremental",
    "rules": {
      "type/no-unnecessary-boolean-literal-compare": "warn"
    },
    "typeAware": true
  },
});

Then run vp run lint.

Related

• Type and script rules
• Rule options
• All rules
• Source code