Add template support for any package.json keys (facebook#8082)

Author: tomvalorsa

docusaurus/docs/custom-templates.md

@@ -58,18 +58,28 @@ You can add whatever files you want in here, but you must have at least the file
 
 ### The `template.json` file
 
-This is where you can define dependencies (only dependencies are supported for now), as well as any custom scripts that your template relies on.
+This is the configuration file for your template. It allows you to define information that should become a part of the generated project's `package.json` file, such as dependencies (only dependencies are supported for now) and any custom scripts that your template relies on. It should be structured as follows:
 
 ```json
 {
-  "dependencies": {
-    "serve": "^11.2.0"
-  },
-  "scripts": {
-    "serve": "serve -s build",
-    "build-and-serve": "npm run build && npm run serve"
+  "package": {
+    "dependencies": {
+      "serve": "^11.2.0"
+    },
+    "scripts": {
+      "serve": "serve -s build",
+      "build-and-serve": "npm run build && npm run serve"
+    },
+    "browserslist": [
+      "defaults",
+      "not IE 11",
+      "not IE_Mob 11",
+      "maintained node versions",
+    ]
   }
 }
 ```
 
+Any values you add for `"dependencies"` and `"scripts"` will be merged with the values used in the initialisation process of `react-scripts`. Any other information you add to `"package"` will be added to the generated project's `package.json` file, replacing any existing values associated with those keys.
+
 For convenience, we always replace `npm run` with `yarn` in your custom `"scripts"`, as well as in your `README` when projects are initialized with yarn.

packages/cra-template-typescript/template.json

@@ -1,12 +1,14 @@
 {
-  "dependencies": {
-    "@testing-library/react": "^9.3.2",
-    "@testing-library/jest-dom": "^4.2.4",
-    "@testing-library/user-event": "^7.1.2",
-    "@types/node": "^12.0.0",
-    "@types/react": "^16.9.0",
-    "@types/react-dom": "^16.9.0",
-    "@types/jest": "^24.0.0",
-    "typescript": "~3.7.2"
+  "package": {
+    "dependencies": {
+      "@testing-library/react": "^9.3.2",
+      "@testing-library/jest-dom": "^4.2.4",
+      "@testing-library/user-event": "^7.1.2",
+      "@types/node": "^12.0.0",
+      "@types/react": "^16.9.0",
+      "@types/react-dom": "^16.9.0",
+      "@types/jest": "^24.0.0",
+      "typescript": "~3.7.2"
+    }
   }
 }

packages/cra-template/template.json

@@ -1,7 +1,9 @@
 {
-  "dependencies": {
-    "@testing-library/react": "^9.3.2",
-    "@testing-library/jest-dom": "^4.2.4",
-    "@testing-library/user-event": "^7.1.2"
+  "package": {
+    "dependencies": {
+      "@testing-library/react": "^9.3.2",
+      "@testing-library/jest-dom": "^4.2.4",
+      "@testing-library/user-event": "^7.1.2"
+    }
   }
 }

packages/react-scripts/fixtures/kitchensink/template.json

@@ -1,10 +1,12 @@
 {
-  "dependencies": {
-    "bootstrap": "4.3.1",
-    "jest": "24.9.0",
-    "node-sass": "4.12.0",
-    "normalize.css": "7.0.0",
-    "prop-types": "15.7.2",
-    "test-integrity": "2.0.1"
+  "package": {
+    "dependencies": {
+      "bootstrap": "4.3.1",
+      "jest": "24.9.0",
+      "node-sass": "4.12.0",
+      "normalize.css": "7.0.0",
+      "prop-types": "15.7.2",
+      "test-integrity": "2.0.1"
+    }
   }
 }

packages/react-scripts/scripts/init.js

@@ -118,11 +118,37 @@ module.exports = function(
     templateJson = require(templateJsonPath);
   }
 
+  const templatePackage = templateJson.package || {};
+
+  // Keys to ignore in templatePackage
+  const templatePackageBlacklist = [
+    'devDependencies',
+    'peerDependencies',
+    'name',
+  ];
+
+  // Keys from templatePackage that will be merged with appPackage
+  const templatePackageToMerge = [
+    'dependencies',
+    'scripts',
+  ];
+
+  // Keys from templatePackage that will be added to appPackage,
+  // replacing any existing entries.
+  const templatePackageToReplace = Object.keys(templatePackage)
+    .filter(key => {
+      return (
+        templatePackageBlacklist.indexOf(key) === -1 &&
+        templatePackageToMerge.indexOf(key) === -1
+      );
+    });
+
   // Copy over some of the devDependencies
   appPackage.dependencies = appPackage.dependencies || {};
 
   // Setup the script rules
-  const templateScripts = templateJson.scripts || {};
+  // TODO: deprecate 'scripts' key directly on templateJson
+  const templateScripts = templatePackage.scripts || templateJson.scripts || {};
   appPackage.scripts = Object.assign(
     {
       start: 'react-scripts start',
@@ -152,6 +178,11 @@ module.exports = function(
   // Setup the browsers list
   appPackage.browserslist = defaultBrowsers;
 
+  // Add templatePackage keys/values to appPackage, replacing existing entries
+  templatePackageToReplace.forEach(key => {
+    appPackage[key] = templatePackage[key];
+  });
+
   fs.writeFileSync(
     path.join(appPath, 'package.json'),
     JSON.stringify(appPackage, null, 2) + os.EOL
@@ -221,7 +252,8 @@ module.exports = function(
   }
 
   // Install additional template dependencies, if present
-  const templateDependencies = templateJson.dependencies;
+  // TODO: deprecate 'dependencies' key directly on templateJson
+  const templateDependencies = templatePackage.dependencies || templateJson.dependencies;
   if (templateDependencies) {
     args = args.concat(
       Object.keys(templateDependencies).map(key => {