⬅️ Back to Table of Contents

📄 default-param-last.ts

📊 Analysis Summary

Metric	Count
🔧 Functions	3
📦 Imports	3
📊 Variables & Constants	3

📚 Table of Contents

• Imports
• Variables & Constants
• Functions

🛠️ File Location:

📂 packages/eslint-plugin/src/rules/default-param-last.ts

📦 Imports

Name	Source
TSESTree	@typescript-eslint/utils
AST_NODE_TYPES	@typescript-eslint/utils
createRule	../util

---

Variables & Constants

Name	Type	Kind	Value	Exported
hasSeenPlainParam	boolean	let/var	false	✗
current	any	const	node.params[i]	✗
param	any	const	`current.type === AST_NODE_TYPES.TSParameterProperty
? current.parameter
: current`	✗

---

Functions

isOptionalParam(node: TSESTree.Parameter): boolean

Code

function isOptionalParam(node: TSESTree.Parameter): boolean {
      return (
        (node.type === AST_NODE_TYPES.ArrayPattern ||
          node.type === AST_NODE_TYPES.AssignmentPattern ||
          node.type === AST_NODE_TYPES.Identifier ||
          node.type === AST_NODE_TYPES.ObjectPattern ||
          node.type === AST_NODE_TYPES.RestElement) &&
        node.optional
      );
    }

• JSDoc:

  /**
       * checks if node is optional parameter
       * @param node the node to be evaluated
       * @private
       */
  

• Parameters:

• node: TSESTree.Parameter
• Return Type: boolean

isPlainParam(node: TSESTree.Parameter): boolean

Code

function isPlainParam(node: TSESTree.Parameter): boolean {
      return !(
        node.type === AST_NODE_TYPES.AssignmentPattern ||
        node.type === AST_NODE_TYPES.RestElement ||
        isOptionalParam(node)
      );
    }

• JSDoc:

  /**
       * checks if node is plain parameter
       * @param node the node to be evaluated
       * @private
       */
  

• Parameters:

• node: TSESTree.Parameter
• Return Type: boolean
• Calls:
• isOptionalParam

`checkDefaultParamLast(node: | TSESTree.ArrowFunctionExpression

    | TSESTree.FunctionDeclaration
    | TSESTree.FunctionExpression): void`

Code

function checkDefaultParamLast(
      node:
        | TSESTree.ArrowFunctionExpression
        | TSESTree.FunctionDeclaration
        | TSESTree.FunctionExpression,
    ): void {
      let hasSeenPlainParam = false;
      for (let i = node.params.length - 1; i >= 0; i--) {
        const current = node.params[i];
        const param =
          current.type === AST_NODE_TYPES.TSParameterProperty
            ? current.parameter
            : current;

        if (isPlainParam(param)) {
          hasSeenPlainParam = true;
          continue;
        }

        if (
          hasSeenPlainParam &&
          (isOptionalParam(param) ||
            param.type === AST_NODE_TYPES.AssignmentPattern)
        ) {
          context.report({ node: current, messageId: 'shouldBeLast' });
        }
      }
    }

• Parameters:
• node: | TSESTree.ArrowFunctionExpression | TSESTree.FunctionDeclaration | TSESTree.FunctionExpression
• Return Type: void
• Calls:
• isPlainParam
• isOptionalParam
• context.report

---