📄 `no-unused-expressions`¶

📊 Analysis Summary¶

Metric	Count
🔧 Functions	2
📦 Imports	6
📊 Variables & Constants	1
📑 Type Aliases	2

📚 Table of Contents¶

Default Export
Imports
Variables & Constants
Functions
Type Aliases

🛠️ File Location:¶

📂 packages/eslint-plugin/src/rules/no-unused-expressions.ts

📤 Default Export¶

export default createRule<Options, MessageIds>({ ... })

Property	Value
`name`	'no-unused-expressions'
`meta.type`	'suggestion'
`meta.docs.description`	'Disallow unused expressions'
`meta.docs.extendsBaseRule`	true
`meta.docs.recommended`	'recommended'
`meta.hasSuggestions`	baseRule.meta.hasSuggestions
`meta.messages`	baseRule.meta.messages
`meta.schema`	baseRule.meta.schema

Entry point: create — documented under Functions.

📦 Imports¶

Name	Source
`AST_NODE_TYPES`	`@typescript-eslint/utils`
`TSESTree`	`@typescript-eslint/utils`
`InferMessageIdsTypeFromRule`	`../util`
`InferOptionsTypeFromRule`	`../util`
`createRule`	`../util`
`getESLintCoreRule`	`../util/getESLintCoreRule`

Variables & Constants¶

Name	Type	Kind	Value	Exported
`defaultOptions`	`Options`	const	`[ { allowShortCircuit: false, allowTaggedTemplates: false, allowTernary: fals...`	✗

Functions¶

`create(context: any, [{ allowShortCircuit = false, a…: any): { ExpressionStatement(node: any): void; }`¶

Parameters:

context any
[{ allowShortCircuit = false, allowTernary = false }] any

Returns: { ExpressionStatement(node: any): void; }

Calls:

baseRule.create
isValidExpression
rules.ExpressionStatement

Code

create(context, [{ allowShortCircuit = false, allowTernary = false }]) {
    const rules = baseRule.create(context);

    function isValidExpression(node: TSESTree.Node): boolean {
      if (allowShortCircuit && node.type === AST_NODE_TYPES.LogicalExpression) {
        return isValidExpression(node.right);
      }
      if (allowTernary && node.type === AST_NODE_TYPES.ConditionalExpression) {
        return (
          isValidExpression(node.alternate) &&
          isValidExpression(node.consequent)
        );
      }
      return (
        (node.type === AST_NODE_TYPES.ChainExpression &&
          node.expression.type === AST_NODE_TYPES.CallExpression) ||
        node.type === AST_NODE_TYPES.ImportExpression
      );
    }

    return {
      ExpressionStatement(node): void {
        if (node.directive || isValidExpression(node.expression)) {
          return;
        }

        const expressionType = node.expression.type;

        if (
          expressionType ===
            TSESTree.AST_NODE_TYPES.TSInstantiationExpression ||
          expressionType === TSESTree.AST_NODE_TYPES.TSAsExpression ||
          expressionType === TSESTree.AST_NODE_TYPES.TSNonNullExpression ||
          expressionType === TSESTree.AST_NODE_TYPES.TSTypeAssertion
        ) {
          rules.ExpressionStatement({
            ...node,
            expression: node.expression.expression,
          });
          return;
        }

        rules.ExpressionStatement(node);
      },
    };
  }

Internal helpers¶

Declared inside another function in this file.

`isValidExpression(node: TSESTree.Node): boolean`¶

Parameters:

node TSESTree.Node

Returns: boolean

Calls:

isValidExpression

Code

function isValidExpression(node: TSESTree.Node): boolean {
      if (allowShortCircuit && node.type === AST_NODE_TYPES.LogicalExpression) {
        return isValidExpression(node.right);
      }
      if (allowTernary && node.type === AST_NODE_TYPES.ConditionalExpression) {
        return (
          isValidExpression(node.alternate) &&
          isValidExpression(node.consequent)
        );
      }
      return (
        (node.type === AST_NODE_TYPES.ChainExpression &&
          node.expression.type === AST_NODE_TYPES.CallExpression) ||
        node.type === AST_NODE_TYPES.ImportExpression
      );
    }

Type Aliases¶

`MessageIds`¶

type MessageIds = InferMessageIdsTypeFromRule<typeof baseRule>;

`Options`¶

type Options = InferOptionsTypeFromRule<typeof baseRule>;

Generated by Syntax Scribe

📄 no-unused-expressions¶