Always forward AST nodes for unresolvable dynamic imports (#2984)

src/Module.ts

@@ -302,18 +302,17 @@ export default class Module {
 	getDynamicImportExpressions(): (string | Node)[] {
 		return this.dynamicImports.map(({ node }) => {
 			const importArgument = node.parent.arguments[0];
-			if (importArgument instanceof TemplateLiteral) {
-				if (importArgument.expressions.length === 0 && importArgument.quasis.length === 1) {
-					return importArgument.quasis[0].value.cooked;
-				}
-			} else if (importArgument instanceof Literal) {
-				if (typeof importArgument.value === 'string') {
-					return importArgument.value;
-				}
-			} else {
-				return importArgument;
+			if (
+				importArgument instanceof TemplateLiteral &&
+				importArgument.quasis.length === 1 &&
+				importArgument.quasis[0].value.cooked
+			) {
+				return importArgument.quasis[0].value.cooked;
+			}
+			if (importArgument instanceof Literal && typeof importArgument.value === 'string') {
+				return importArgument.value;
 			}
-			return undefined as any;
+			return importArgument;
 		});
 	}
 

test/form/samples/dynamic-import-unresolvable/_config.js

@@ -0,0 +1,20 @@
+const assert = require('assert');
+
+module.exports = {
+	solo: true,
+	description: 'Returns the raw AST nodes for unresolvable dynamic imports',
+	options: {
+		plugins: [
+			{
+				resolveDynamicImport(specifier) {
+					assert.ok(specifier);
+					assert.strictEqual(typeof specifier, 'object');
+					if (specifier.type !== 'TemplateLiteral' && specifier.type !== 'Literal') {
+						throw new Error(`Unexpected specifier type ${specifier.type}.`);
+					}
+					return false;
+				}
+			}
+		]
+	}
+};

test/form/samples/dynamic-import-unresolvable/_expected.js

@@ -0,0 +1,3 @@
+import(`${globalVar}`);
+import(`My ${globalVar}`);
+import(7);

test/form/samples/dynamic-import-unresolvable/main.js

@@ -0,0 +1,3 @@
+import(`${globalVar}`);
+import(`My ${globalVar}`);
+import(7);