Repository: ember-cli/ember-cli (js)

Issue:
Tracked properties module not included in new ember projects
---

Output from `ember version --verbose && npm --version && yarn --version`:
```
ember-cli: 3.15.1
http_parser: 2.8.0
node: 10.13.0
v8: 6.8.275.32-node.36
uv: 1.23.2
zlib: 1.2.11
ares: 1.14.0
modules: 64
nghttp2: 1.34.0
napi: 3
openssl: 1.1.0i
icu: 62.1
unicode: 11.0
cldr: 33.1
tz: 2018e
os: darwin x64
6.4.1
1.12.3
```

The [guides](https://guides.emberjs.com/v3.15.0/upgrading/current-edition/tracked-properties/) imply that tracked properties are included out of the box in a new ember-cli project. 

However, generating a new ember-cli project on 3.15 does not include the module @glimmer/tracking -- leading to confusion for users.

Should a new ember-cli project include @glimmer/tracking?

Pull request:
Add @glimmer/tracking to default blueprint.
This package isn't _strictly_ required (because we polyfill replace it with a Ember.* path at runtime), but having it is much easier to explain (aides consumers in TypeScript land, matches the similar @glimmer/component dependency, etc).

Fixes #9003

Patch:
diff --git a/blueprints/app/files/package.json b/blueprints/app/files/package.json
index ee6dde361..810bdb6c5 100644
--- a/blueprints/app/files/package.json
+++ b/blueprints/app/files/package.json
@@ -20,6 +20,7 @@
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",
     "@glimmer/component": "^1.0.0",
+    "@glimmer/tracking": "^1.0.0",
     "babel-eslint": "^10.0.3",
     "broccoli-asset-rev": "^3.0.0",
     "ember-auto-import": "^1.5.3",


Test patch:
diff --git a/tests/fixtures/addon/npm/package.json b/tests/fixtures/addon/npm/package.json
index 481c53d58..073f4ccea 100644
--- a/tests/fixtures/addon/npm/package.json
+++ b/tests/fixtures/addon/npm/package.json
@@ -27,6 +27,7 @@
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",
     "@glimmer/component": "^1.0.0",
+    "@glimmer/tracking": "^1.0.0",
     "babel-eslint": "^10.0.3",
     "broccoli-asset-rev": "^3.0.0",
     "ember-auto-import": "^1.5.3",
diff --git a/tests/fixtures/addon/yarn/package.json b/tests/fixtures/addon/yarn/package.json
index 8fe5a299a..72bef03dc 100644
--- a/tests/fixtures/addon/yarn/package.json
+++ b/tests/fixtures/addon/yarn/package.json
@@ -27,6 +27,7 @@
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",
     "@glimmer/component": "^1.0.0",
+    "@glimmer/tracking": "^1.0.0",
     "babel-eslint": "^10.0.3",
     "broccoli-asset-rev": "^3.0.0",
     "ember-auto-import": "^1.5.3",
diff --git a/tests/fixtures/app/npm/package.json b/tests/fixtures/app/npm/package.json
index a157556c3..9a7e51c54 100644
--- a/tests/fixtures/app/npm/package.json
+++ b/tests/fixtures/app/npm/package.json
@@ -20,6 +20,7 @@
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",
     "@glimmer/component": "^1.0.0",
+    "@glimmer/tracking": "^1.0.0",
     "babel-eslint": "^10.0.3",
     "broccoli-asset-rev": "^3.0.0",
     "ember-auto-import": "^1.5.3",
diff --git a/tests/fixtures/app/yarn/package.json b/tests/fixtures/app/yarn/package.json
index 0c481fed4..836162364 100644
--- a/tests/fixtures/app/yarn/package.json
+++ b/tests/fixtures/app/yarn/package.json
@@ -20,6 +20,7 @@
   "devDependencies": {
     "@ember/optional-features": "^1.1.0",
     "@glimmer/component": "^1.0.0",
+    "@glimmer/tracking": "^1.0.0",
     "babel-eslint": "^10.0.3",
     "broccoli-asset-rev": "^3.0.0",
     "ember-auto-import": "^1.5.3",