Fix #10409 by ignoring self-referential browser aliases in package.json.

tools/isobuild/import-scanner.js

@@ -1422,6 +1422,12 @@ export default class ImportScanner {
           return;
         }
 
+        // Ignore useless self-referential browser aliases, to fix
+        // https://github.com/meteor/meteor/issues/10409.
+        if (target.id === source.id) {
+          return;
+        }
+
         Object.assign(alias, target);
         alias.absModuleId = this._getAbsModuleId(target.path);
 

tools/tests/apps/modules/package-lock.json

@@ -1210,6 +1210,11 @@
         "minimist": "0.0.8"
       }
     },
+    "mobx": {
+      "version": "5.8.0",
+      "resolved": "https://registry.npmjs.org/mobx/-/mobx-5.8.0.tgz",
+      "integrity": "sha512-NsZB+9bF5j+nv9Qwk6bNeE3np26a4TbTGkMpOLf6o1zXoM9BtHPQn/00px4uZ2AXJXtQML5P4MEWdMm6icMIfQ=="
+    },
     "moment": {
       "version": "2.22.2",
       "resolved": "https://registry.npmjs.org/moment/-/moment-2.22.2.tgz",

tools/tests/apps/modules/package.json

@@ -17,6 +17,7 @@
     "jsx-import-test": "file:imports/links/jsx-import-test",
     "lodash-es": "^4.17.7",
     "meteor-node-stubs": "^0.4.1",
+    "mobx": "5.8.0",
     "moment": "^2.22.2",
     "mssql": "^3.1.1",
     "mysql": "^2.15.0",

tools/tests/apps/modules/tests.js

@@ -660,3 +660,11 @@ describe("imported *.tests.js modules", () => {
     assert.strictEqual(name, "imported.tests.js");
   });
 });
+
+describe("issue #10409", () => {
+  it("should be able to import mobx@5.8.0", () => {
+    const { observable, action } = require("mobx");
+    assert.strictEqual(typeof observable, "function");
+    assert.strictEqual(typeof action, "function");
+  });
+});