From 3f7fc92bc89fdad4ddcbc3cb7abfde8a2429f0bd Mon Sep 17 00:00:00 2001
From: Manuel Mujica <manuel.expat@gmail.com>
Date: Mon, 22 Jan 2018 15:08:02 -0700
Subject: [PATCH] Allow plugins to include the slim dynamic loader

Closes #931
---
 lib/graph/slim_graph.js          | 18 ++++++++++++++++--
 test/slim/dynamic/foo.plug       |  1 +
 test/slim/dynamic/main.js        |  1 +
 test/slim/dynamic/plug.js        | 15 +++++++++++++++
 test/slim/dynamic/stealconfig.js |  3 +++
 test/slim_build_test.js          | 19 +++++++++++++++++++
 6 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 test/slim/dynamic/foo.plug
 create mode 100644 test/slim/dynamic/main.js
 create mode 100644 test/slim/dynamic/plug.js
 create mode 100644 test/slim/dynamic/stealconfig.js

diff --git a/lib/graph/slim_graph.js b/lib/graph/slim_graph.js
index b2e66c88..9d748f5c 100644
--- a/lib/graph/slim_graph.js
+++ b/lib/graph/slim_graph.js
@@ -57,7 +57,10 @@ module.exports = function(options) {
 					target: options.target,
 					slimConfig: options.slimConfig,
 					plugins: !!nonJsBundles.length,
-					mainModuleId: getMainModuleId(options.graph, options.mains[0])
+					mainModuleId: getMainModuleId(
+						options.graph,
+						options.mains[0]
+					)
 				})
 			])
 		);
@@ -102,7 +105,9 @@ module.exports = function(options) {
 					sharedBundles: sharedBundles,
 					plugins: !!nonJsBundles.length,
 					slimConfig: options.slimConfig,
-					progressive: !!secondaryBundles.length,
+					progressive:
+						needsDynamicLoader(options.slimConfig) ||
+						!!secondaryBundles.length,
 					mainModuleId: getMainModuleId(options.graph, mainName)
 				})
 			];
@@ -122,6 +127,15 @@ module.exports = function(options) {
 	return slimmedBundles;
 };
 
+/**
+ * Whether the slim loader should support dynamic loading
+ * @param {Object} config
+ * @return {boolean}
+ */
+function needsDynamicLoader(config) {
+	return config.needsDynamicLoader === true;
+}
+
 /**
  * Whether there are multiple mains to be built
  * @param {Array} mains
diff --git a/test/slim/dynamic/foo.plug b/test/slim/dynamic/foo.plug
new file mode 100644
index 00000000..7e9668e7
--- /dev/null
+++ b/test/slim/dynamic/foo.plug
@@ -0,0 +1 @@
+"foo"
\ No newline at end of file
diff --git a/test/slim/dynamic/main.js b/test/slim/dynamic/main.js
new file mode 100644
index 00000000..36aab8db
--- /dev/null
+++ b/test/slim/dynamic/main.js
@@ -0,0 +1 @@
+require("foo.plug!plug");
\ No newline at end of file
diff --git a/test/slim/dynamic/plug.js b/test/slim/dynamic/plug.js
new file mode 100644
index 00000000..3034a5da
--- /dev/null
+++ b/test/slim/dynamic/plug.js
@@ -0,0 +1,15 @@
+"format cjs";
+var loader = require("@loader");
+var local = loader.localLoader || loader;
+
+if (local.slimConfig) {
+	local.slimConfig.needsDynamicLoader = true;
+}
+
+exports.translate = function plug(load) {
+	return `
+		define(function() {
+			return ${load.source};
+		});
+	`;
+};
diff --git a/test/slim/dynamic/stealconfig.js b/test/slim/dynamic/stealconfig.js
new file mode 100644
index 00000000..5f703aa0
--- /dev/null
+++ b/test/slim/dynamic/stealconfig.js
@@ -0,0 +1,3 @@
+steal.config({
+	main: "main"
+});
diff --git a/test/slim_build_test.js b/test/slim_build_test.js
index 61be0ef3..150fc7fb 100644
--- a/test/slim_build_test.js
+++ b/test/slim_build_test.js
@@ -785,4 +785,23 @@ describe("slim builds", function() {
 				close();
 			});
 	});
+
+	it("adds dynamic loading if config flag set", function() {
+		var base = path.join(__dirname, "slim", "dynamic");
+		var config = { config: path.join(base, "stealconfig.js") };
+
+		return rmdir(path.join(base, "dist"))
+			.then(function() {
+				return optimize(config, { quiet: true, minify: false });
+			})
+			.then(function() {
+				return readFile(path.join(base, "dist", "bundles", "main.js"));
+			})
+			.then(function(buffer) {
+				assert.ok(
+					/stealRequire\.dynamic = function/.test(buffer.toString()),
+					"slim loader should support dynamic imports"
+				);
+			});
+	});
 });