fix(bootstrap): Respect --force-local option (#2104)

Before this change, `--force-local` option was not respected and monorepo-local packages outside of the defined --scope were still installed from the npm registry.

This commit fixes the code handling `--force-local` logic, so that:
- Local packages are resolved as links within the monorepo
- The following warning IS NOT printed anymore:
  _Installing local packages that do not match filters from registry_

commands/bootstrap/__tests__/__snapshots__/bootstrap-command.test.js.snap

@@ -319,9 +319,6 @@ Object {
     "bar@^2.0.0",
     "foo@^1.0.0",
   ],
-  "packages/package-4": Array [
-    "package-3@^1.0.0",
-  ],
 }
 `;
 
@@ -332,6 +329,21 @@ Array [
     "dest": "packages/package-4/node_modules/@test/package-1",
     "type": "junction",
   },
+  Object {
+    "_src": "packages/package-3",
+    "dest": "packages/package-4/node_modules/package-3",
+    "type": "junction",
+  },
+  Object {
+    "_src": "packages/package-3/cli1.js",
+    "dest": "packages/package-4/node_modules/.bin/package3cli1",
+    "type": "exec",
+  },
+  Object {
+    "_src": "packages/package-3/cli2.js",
+    "dest": "packages/package-4/node_modules/.bin/package3cli2",
+    "type": "exec",
+  },
 ]
 `;
 

commands/bootstrap/__tests__/bootstrap-command.test.js

@@ -313,6 +313,24 @@ describe("BootstrapCommand", () => {
       expect(symlinkedDirectories(testDir)).toMatchSnapshot();
     });
 
+    it("should respect --force-local when a single package is in scope", async () => {
+      const testDir = await initFixture("basic");
+
+      await lernaBootstrap(testDir)("--scope", "package-4", "--force-local");
+
+      // no packages were installed from the registry
+      const installed = installedPackagesInDirectories(testDir);
+      expect(installed["packages/package-4"] || []).toEqual([]);
+
+      // package-3 was resolved as a local symlink
+      const symlinked = symlinkedDirectories(testDir);
+      expect(symlinked).toContainEqual({
+        _src: "packages/package-3",
+        dest: "packages/package-4/node_modules/package-3",
+        type: "junction",
+      });
+    });
+
     it("should not update package.json when filtering", async () => {
       const testDir = await initFixture("basic");
 

commands/bootstrap/index.js

@@ -161,7 +161,7 @@ class BootstrapCommand extends Command {
     chain = chain.then(filteredPackages => {
       this.filteredPackages = filteredPackages;
 
-      if (filteredPackages.length !== this.targetGraph.size) {
+      if (filteredPackages.length !== this.targetGraph.size && !this.options.forceLocal) {
         this.logger.warn("bootstrap", "Installing local packages that do not match filters from registry");
 
         // an explicit --scope, --ignore, or --since should only symlink the targeted packages, no others