Handle ChainExpression as conditional

Author: matz3

lib/lbt/analyzer/JSModuleAnalyzer.js

@@ -66,7 +66,7 @@ const EnrichedVisitorKeys = (function() {
 		BreakStatement: [],
 		CallExpression: [], // special handling
 		CatchClause: ["param", "body"],
-		ChainExpression: [],
+		ChainExpression: ["expression"],
 		ClassBody: [],
 		ClassDeclaration: [],
 		ClassExpression: [],

test/fixtures/lbt/modules/es6-syntax.js

@@ -40,9 +40,7 @@ sap.ui.define([
 	};
 
 	// chain expression
-
-	// TODO: This is not detected as conditional dependency
-	// sap?.ui?.require(["conditional/module4"]);
+	sap?.ui?.require(["conditional/module4"]);
 
 	// iterator pattern
 	const iterator = {

test/lib/lbt/analyzer/JSModuleAnalyzer.js

@@ -495,7 +495,7 @@ test("ES6 Syntax", (t) => {
 			// "conditional/module11.js", // TODO: see es6-syntax.js
 			"conditional/module2.js",
 			"conditional/module3.js",
-			// "conditional/module4.js", // TODO: see es6-syntax.js
+			"conditional/module4.js",
 			"conditional/module6.js",
 			"conditional/module7.js",
 			"conditional/module8.js",
@@ -644,6 +644,38 @@ test("ES6 Template Literal in sap.ui.predefine", (t) => {
 	});
 });
 
+test("ChainExpression", (t) => {
+	const content = `
+	sap.ui.define(['require', 'static/module1'], (require) => {
+		sap?.ui?.require?.(['conditional/module2']);
+		sap?.ui?.requireSync?.('conditional/module3');
+		jQuery?.sap?.require?.('conditional.module4');
+		require?.(['conditional/module5']);
+	});`;
+	const info = analyzeString(content, "modules/ChainExpression.js");
+
+	const expected = [
+		"conditional/module2.js",
+		"conditional/module3.js",
+		"conditional/module4.js",
+		"conditional/module5.js",
+		"jquery.sap.global.js",
+		"static/module1.js",
+	];
+	const actual = info.dependencies.sort();
+	t.deepEqual(actual, expected, "module dependencies should match");
+	expected.forEach((dep) => {
+		t.is(info.isConditionalDependency(dep), /^conditional\//.test(dep),
+			`only dependencies to 'conditional/*' modules should be conditional (${dep})`);
+		t.is(info.isImplicitDependency(dep), !/^(?:conditional|static)\//.test(dep),
+			`all dependencies other than 'conditional/*' and 'static/*' should be implicit (${dep})`);
+	});
+	t.false(info.dynamicDependencies,
+		`no use of dynamic dependencies should have been detected`);
+	t.false(info.rawModule,
+		`ui5 module`);
+});
+
 test("Dynamic import (declare/require)", (t) => {
 	return analyze("modules/declare_dynamic_require.js").then((info) => {
 		t.true(info.dynamicDependencies,