could-implement.ts

/**
 * @license Use of this source code is governed by an MIT-style license that
 * can be found in the LICENSE file at https://github.com/cartant/tsutils-etc
 */

import * as ts from "typescript";

export function couldImplement(
  type: ts.Type,
  name: string | RegExp,
  qualified?: {
    name: RegExp;
    typeChecker: ts.TypeChecker;
  }
): boolean {
  const { symbol } = type;
  if (symbol) {
    const { valueDeclaration } = symbol;
    if (valueDeclaration && ts.isClassDeclaration(valueDeclaration)) {
      const { heritageClauses } = valueDeclaration;
      if (heritageClauses) {
        const implemented = heritageClauses.some(
          ({ token, types }) =>
            token === ts.SyntaxKind.ImplementsKeyword &&
            types.some((node) => isMatchingNode(node, name, qualified))
        );
        if (implemented) {
          return true;
        }
      }
    }
  }
  return false;
}

function isMatchingNode(
  node: ts.ExpressionWithTypeArguments,
  name: string | RegExp,
  qualified?: {
    name: RegExp;
    typeChecker: ts.TypeChecker;
  }
): boolean {
  const { expression } = node;
  if (qualified) {
    const type = qualified.typeChecker.getTypeAtLocation(expression);
    if (type) {
      const qualifiedName = qualified.typeChecker.getFullyQualifiedName(
        type.symbol
      );
      if (!qualified.name.test(qualifiedName)) {
        return false;
      }
    }
  }
  const text = expression.getText();
  return typeof name === "string" ? text === name : Boolean(text.match(name));
}