(NOT FOR MERGING)convert to use yarn workspaces

.prettierrc

@@ -0,0 +1,6 @@
+printWidth: 100
+semi: true
+singleQuote: true
+trailingComma: all
+bracketSpacing: true
+jsxBracketSameLine: false

README.md

@@ -1,149 +1,42 @@
-# Lerna + Project References
+# Lerna monorepo + yarn workspaces + typescript project references + flattened build
 
-This is a "bare minimum" repo that shows one way to configure TypeScript Project References with lerna. There are a lot of different ways you can set things up and this isn't intended to be authoratitive guidance or exclusionary of other ways that might work better in your project.
+Lerna, yarn workspaces, and a direct file import (not just index) with a flattened build output.
 
-# Setting up this repo
+**It works!**
 
-```
-> git clone https://github.com/RyanCavanaugh/learn-a.git
-> cd learn-a
-> npm install
-> lerna bootstrap
-> tsc -b packages
-```
+## Flattened build?
 
-Note that you'll need a 3.0 version of `tsc` (currently available at `npm install -g typescript@next`).
+Our packages (and many others like `@material-ui/core`) are flattened when published to prevent unnecessarily deep import paths.
 
-### General Structure
+The rough equivalent of:
 
-As with a normal lerna repo, there's a `packages` folder. Inside we have three creatively named packages `pkg1`, `pkg2`, and `pkg3`.
-
-```
-packages/
-| tsconfig.settings.json
-| tsconfig.json
-| pkg1/
-  | tsconfig.json
-  | src/
-  | | (typescript files)        
-  | lib/
-  | | (javascript files)
-  | | (.d.ts files)
-| pkg2/
-  | (same as pkg1)
-| pkg3/
-  | (same as pkg1)
+```bash
+cd packages/pkg1
+yarn tsc
+cd lib
+cp package.json .
+# modify module/typings properties to be ./index
+npm publish
 ```
 
-Let's review each file in the repo and explain what's going on
-
-#### `tsconfig.settings.json`
-```js
-{
-    "compilerOptions": {
-        // Always include these settings
-        "composite": true,
-        "declaration": true,
-        "declarationMap": true,
-        "sourceMap": true,
-
-        // These settings are totally up to you        
-        "esModuleInterop": true,
-        "target": "es5",
-        "module": "commonjs",
-        "strict": true
-    }
-}
-```
-This file contains the "default" settings that all packages will use for compilation. You will definitely want the `composite`, `declaration`, `declarationMap`, and `sourceMap` settings enabled for all projects, so include those in this file. Other settings, like `target` and `strict`, can be specified here if you'd like to enable them by default. You'll also be able to override these settings on a per-package basis if needed.
-
-#### `tsconfig.json`
-```json
-{
-    "files": [],
-    "references": [
-        { "path": "pkg1" },
-        { "path": "pkg2" },
-        { "path": "pkg3" }
-    ]
-}
-```
-This file is pretty simple - simply list the packages that need to be built with `tsc` in the `references` array.
-You should also include `"files": []` in this file - this will prevent an incorrect invocation of `tsc` without `-b` from trying to build the entire packages folder source files as one compilation (which will fail, but drop a bunch of .js files in random places as an annoying side effect).
-
-#### `packages/pkg2/tsconfig.json`
-
-We'll just cover one of the `pkg1` / `pkg2` / `pkg3` packages since they're basically identical for the purposes of this demo. Here's `pkg2`'s `tsconfig.json`:
-```json
-{
-  "extends": "../tsconfig.settings.json",
-  "compilerOptions": {
-    "outDir": "lib",
-    "rootDir": "src"
-  },
-  "references": [
-    { "path": "../pkg1" }
-  ]
-}
-```
-The `extends` property pulls in the settings we wrote in `tsconfig.settings.json`, so we don't have to duplicate any settings described there.
-
-In `compilerOptions`, we've set `outDir` to `lib` and `rootDir` to `src`, then placed all my `.ts` files in `src`. This means `src/index.ts` will build to `lib/index.js` and `lib/index.d.ts`. This is also the place where you could override settings like `strict` or `target` if you needed to change them on a per-project basis.
-
-In the `references` array, we list the paths to the other projects' `tsconfig.json` files (or containing folders, as shown here). This will both ensure that we locate the `.d.ts` files correctly, and set up a proper build ordering.
+This makes the `index` and `foo` siblings at the root of the package, resolvable at the same level (no `lib` folder). It is also the reason for the two entries in the path aliases above. The path aliases above allow a source monorepo to behave like a published package, which I feel strongly is an essential need for project-references to be usable.
 
-#### `packages/pkg2/src/index.ts`
-```ts
-import * as p1 from '@ryancavanaugh/pkg1';
+## Error without path alias
 
-export function fn4() {
-    p1.fn();
-}
 ```
-Nothing unusual going on here. We import and export with the usual syntax. Notably, if you open this repo in an editor, you can still "Go to Definition (F12)" on `p1.fn` here and land in `pkg1/foo.ts` - the original sourcecode - even though "under the covers" it's using the much faster `.d.ts` file for typechecking.
+packages/pkg2/src/index.ts:2:20 - error TS2307: Cannot find module '@ryancavanaugh/pkg1/foo'.
 
-#### `packages/pkg2/package.json`
-Here are the relevant excerpts from the `package.json`:
-```json
-{
-  "main": "lib/index.js",
-  "typings": "lib/index.d.ts",
-  "scripts": {
-    "prepublishOnly": "tsc -b ."
-  },
-  "devDependencies": {
-    "typescript": "^3.0.0-dev.20180626"
-  }
-}
+2 import { fn } from '@ryancavanaugh/pkg1/foo';
 ```
+**Solution:** If you receive an error like this and you expect a flattened final build structure, you may need to setup the `baseUrl` and `paths`.  See `pkg3/tsconfig.json`.
 
-Because we build to `lib`, we need to set `main` to the `.js` file there *and* `typings` to the `.d.ts` file.
-
-In `scripts`, we use the local copy of `tsc` (listed here as a dev dependency) to run a *build mode* compilation on the project. This will ensure that the `lib` folder is always built before `npm publish`, and blocks any publishes that try to push non-compiling code.
-
-#### `packages/pkg2/.npmignore` / `packages/pkg2/.gitignore`
-
-*.gitignore*
-```
-lib/
-```
-
-*.npmignore*
-```
-# Empty, but needs to exist
-```
-
-The `.gitignore` stops us from checking in build outputs, which is generally a good idea. By default, `npm` won't publish files that are ignored by `git`, so we need a separate `.npmignore` file so that the `lib` folder still gets published!
-
-# Workflow
-
-All your lerna commands and workflow will work as expected here.
+# Setting up this repo
 
-To build the TypeScript projects, you can run individual builds with `tsc -b`:
 ```
- > tsc -b packages/pkg3
-```
-Or just build everything:
-```
- > tsc -b packages
+> git clone https://github.com/rosskevin/learn-a.git
+> git checkout yarn-workspaces-TS2307
+> cd learn-a
+> yarn install
+> lerna bootstrap
+> yarn clean:build && yarn build
 ```

lerna.json

@@ -1,7 +1,6 @@
 {
   "lerna": "2.11.0",
-  "packages": [
-    "packages/*"
-  ],
-  "version": "3.0.2"
+  "version": "3.0.2",
+  "npmClient": "yarn",
+  "useWorkspaces": true
 }

package.json

@@ -1,6 +1,17 @@
 {
-	"devDependencies": {
-		"lerna": "^2.11.0",
-		"typescript": "^3.0.0-dev.20180626"
-	}
+  "private": true,
+  "workspaces": [
+    "packages/*"
+  ],
+  "scripts": {
+    "build": "tsc -b",
+    "clean:build": "rm -rf ./packages/*/build",
+    "lint": "tslint --project ./packages/tsconfig.lint.json",
+    "lint:fix": "tslint --project ./packages/tsconfig.lint.json --fix"
+  },
+  "devDependencies": {
+    "lerna": "^3.2.1",
+    "tslint": "^5.11.0",
+    "typescript": "next"
+  }
 }

packages/pkg1/package.json

@@ -12,6 +12,6 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
-    "typescript": "^3.0.0-dev.20180626"
+    "typescript": "next"
   }
 }

packages/pkg1/src/foo.ts

@@ -1,3 +1,3 @@
 export function fn() {
-    return "Hello world";
+    return 'Hello world';
 }

packages/pkg1/src/index.ts

@@ -1 +1 @@
-export * from "./foo";
+export * from './foo';

packages/pkg2/package.json

@@ -15,6 +15,6 @@
     "@ryancavanaugh/pkg1": "^3.0.2"
   },
   "devDependencies": {
-    "typescript": "^3.0.0-dev.20180626"
+    "typescript": "next"
   }
 }

packages/pkg2/src/index.ts

@@ -1,6 +1,6 @@
-import * as p1 from '@ryancavanaugh/pkg1';
+// import * as p1 from '@ryancavanaugh/pkg1'; // works
+import { fn } from '@ryancavanaugh/pkg1/foo'; // works with path alias setup
 
 export function fn4() {
-    p1.fn();
+  fn();
 }
-

packages/pkg2/tsconfig.json

@@ -2,9 +2,12 @@
   "extends": "../tsconfig.settings.json",
   "compilerOptions": {
     "outDir": "lib",
-    "rootDir": "src"
+    "rootDir": "src",
+    "traceResolution": true,
+    "baseUrl": "./",
+    "paths": {
+      "@ryancavanaugh/pkg1/*": ["../pkg1/src/*"]
+    }
   },
-  "references": [
-    { "path": "../pkg1" }
-  ]
-}
+  "references": [{ "path": "../pkg1" }]
+}

packages/pkg3/package.json

@@ -16,6 +16,6 @@
     "@ryancavanaugh/pkg2": "^3.0.2"
   },
   "devDependencies": {
-    "typescript": "^3.0.0-dev.20180626"
+    "typescript": "next"
   }
 }

packages/pkg3/src/index.ts

@@ -1,5 +1,7 @@
-import * as p1 from "@ryancavanaugh/pkg1";
-import * as p2 from "@ryancavanaugh/pkg2";
+import * as p1 from '@ryancavanaugh/pkg1';
+import { fn } from '@ryancavanaugh/pkg1/foo'; // works with path alias setup
+import * as p2 from '@ryancavanaugh/pkg2';
 
 p1.fn();
 p2.fn4();
+fn();

packages/pkg3/tsconfig.json

@@ -2,10 +2,12 @@
   "extends": "../tsconfig.settings.json",
   "compilerOptions": {
     "outDir": "lib",
-    "rootDir": "src"
+    "rootDir": "src",
+    "baseUrl": "./",
+    "paths": {
+      "@ryancavanaugh/pkg1/*": ["../pkg1/src/*"],
+      "@ryancavanaugh/pkg2/*": ["../pkg2/src/*"]
+    }
   },
-  "references": [
-    { "path": "../pkg1" },
-    { "path": "../pkg2" }
-  ]
-}
+  "references": [{ "path": "../pkg1" }, { "path": "../pkg2" }]
+}

packages/tsconfig.lint.json

@@ -0,0 +1,6 @@
+{
+  // This file is only necessary until tslint has TS3 references support
+  // See also https://github.com/palantir/tslint/issues/4137
+  "extends": "./tsconfig.settings.json",
+  "include": ["./*/src/**.ts", "./*/test/**.ts"]
+}

packages/tsconfig.settings.json

@@ -1,12 +1,13 @@
 {
-    "compilerOptions": {
-        "target": "es5",
-        "module": "commonjs",
-        "declaration": true,
-        "declarationMap": true,
-        "sourceMap": true,
-        "strict": true,
-        "composite": true,
-        "esModuleInterop": true
-    }
+  "compilerOptions": {
+    "target": "es5",
+    "module": "commonjs",
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true,
+    "strict": true,
+    "composite": true,
+    "esModuleInterop": true,
+    "moduleResolution": "node"
+  }
 }