Method handler

lib/ConstPlugin.js:166–497

(parser)

				 * @param {JavascriptParser} parser the parser
				 */
				const handler = (parser) => {
					parser.hooks.terminate.tap(PLUGIN_NAME, (_statement) => true);
					parser.hooks.statementIf.tap(PLUGIN_NAME, (statement) => {
						if (parser.scope.isAsmJs) return;
						const param = parser.evaluateExpression(statement.test);
						const bool = param.asBool();
						if (typeof bool === "boolean") {
							if (!param.couldHaveSideEffects()) {
								const dep = new ConstDependency(
									`${bool}`,
									/** @type {Range} */ (param.range)
								);
								dep.loc = /** @type {SourceLocation} */ (statement.loc);
								parser.state.module.addPresentationalDependency(dep);
							} else {
								parser.walkExpression(statement.test);
							}
							const branchToRemove = bool
								? statement.alternate
								: statement.consequent;
							if (branchToRemove) {
								this.eliminateUnusedStatement(parser, branchToRemove, true);
							}
							return bool;
						}
					});
					parser.hooks.unusedStatement.tap(PLUGIN_NAME, (statement) => {
						if (
							parser.scope.isAsmJs ||
							// Check top level scope here again
							parser.scope.topLevelScope === true
						) {
							return;
						}
						this.eliminateUnusedStatement(parser, statement, false);
						return true;
					});
					parser.hooks.expressionConditionalOperator.tap(
						PLUGIN_NAME,
						(expression) => {
							if (parser.scope.isAsmJs) return;
							const param = parser.evaluateExpression(expression.test);
							const bool = param.asBool();
							if (typeof bool === "boolean") {
								if (!param.couldHaveSideEffects()) {
									const dep = new ConstDependency(
										` ${bool}`,
										/** @type {Range} */ (param.range)
									);
									dep.loc = /** @type {SourceLocation} */ (expression.loc);
									parser.state.module.addPresentationalDependency(dep);
								} else {
									parser.walkExpression(expression.test);
								}
								// Expressions do not hoist.
								// It is safe to remove the dead branch.
								//
								// Given the following code: