fix(publish): Allow per-leaf subdirectory publishing

Thanks @heavypennies for the original implementation.

Closes #2109

commands/publish/README.md

@@ -98,6 +98,9 @@ lerna publish --contents dist
 # publish the "dist" subfolder of every Lerna-managed leaf package
 ```
 
+**NOTE:** You should wait until the `postpublish` lifecycle phase (root or leaf) to clean up this generated subdirectory,
+as the generated package.json is used during package upload (_after_ `postpack`).
+
 ### `--dist-tag <tag>`
 
 ```sh
@@ -275,6 +278,16 @@ You can customize the dist-tag on a per-package basis by setting [`tag`](https:/
 - Passing [`--dist-tag`](#--dist-tag-tag) will _overwrite_ this value.
 - This value is _always_ ignored when [`--canary`](#--canary) is passed.
 
+### `publishConfig.directory`
+
+This _non-standard_ field allows you to customize the published subdirectory just like [`--contents`](#--contents-dir), but on a per-package basis. All other caveats of `--contents` still apply.
+
+```json
+  "publishConfig": {
+    "directory": "dist"
+  }
+```
+
 ## LifeCycle Events
 
 Lerna will run [npm lifecycle scripts](https://docs.npmjs.com/misc/scripts#description) during `lerna publish` in the following order:

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

@@ -21,6 +21,7 @@ const getNpmUsername = require("../lib/get-npm-username");
 const verifyNpmPackageAccess = require("../lib/verify-npm-package-access");
 
 // helpers
+const commitChangeToPackage = require("@lerna-test/commit-change-to-package");
 const loggingOutput = require("@lerna-test/logging-output");
 const initFixture = require("@lerna-test/init-fixture")(__dirname);
 
@@ -262,6 +263,30 @@ Map {
     });
   });
 
+  describe("publishConfig.directory", () => {
+    it("mimics effect of --contents, but per-package", async () => {
+      const cwd = await initFixture("lifecycle");
+
+      await commitChangeToPackage(cwd, "package-1", "chore: setup", {
+        publishConfig: {
+          directory: "dist",
+        },
+      });
+
+      await lernaPublish(cwd)();
+
+      expect(packDirectory).toHaveBeenCalledWith(
+        expect.objectContaining({ name: "package-1" }),
+        expect.stringMatching(/packages\/package-1\/dist$/),
+        expect.any(Object)
+      );
+      expect(packDirectory).toHaveBeenCalledWith(
+        expect.objectContaining({ name: "package-2" }),
+        expect.stringMatching(/packages\/package-2$/),
+        expect.any(Object)
+      );
+    });
+  });
   describe("in a cyclical repo", () => {
     it("should throw an error with --reject-cycles", async () => {
       expect.assertions(1);

commands/publish/index.js

@@ -595,16 +595,22 @@ class PublishCommand extends Command {
     }
 
     const { contents } = this.options;
-    const getLocation = contents ? pkg => path.resolve(pkg.location, contents) : pkg => pkg.location;
+
+    if (contents) {
+      // globally override directory to publish
+      for (const pkg of this.packagesToPublish) {
+        pkg.contents = contents;
+      }
+    }
 
     const opts = this.conf.snapshot;
     const mapper = pPipe(
       [
         this.options.requireScripts && (pkg => this.execScript(pkg, "prepublish")),
 
         pkg =>
-          pulseTillDone(packDirectory(pkg, getLocation(pkg), opts)).then(packed => {
-            tracker.verbose("packed", pkg.name, path.relative(this.project.rootPath, getLocation(pkg)));
+          pulseTillDone(packDirectory(pkg, pkg.contents, opts)).then(packed => {
+            tracker.verbose("packed", pkg.name, path.relative(this.project.rootPath, pkg.contents));
             tracker.completeWork(1);
 
             // store metadata for use in this.publishPacked()

core/package/__tests__/core-package.test.js

@@ -64,6 +64,41 @@ describe("Package", () => {
     });
   });
 
+  describe("get .contents", () => {
+    it("returns pkg.location by default", () => {
+      const pkg = factory({ version: "1.0.0" });
+      expect(pkg.contents).toBe(path.normalize("/root/path/to/package"));
+    });
+
+    it("returns pkg.publishConfig.directory when present", () => {
+      const pkg = factory({
+        version: "1.0.0",
+        publishConfig: {
+          directory: "dist",
+        },
+      });
+      expect(pkg.contents).toBe(path.normalize("/root/path/to/package/dist"));
+    });
+
+    it("returns pkg.location when pkg.publishConfig.directory is not present", () => {
+      const pkg = factory({
+        version: "1.0.0",
+        publishConfig: {
+          tag: "next",
+        },
+      });
+      expect(pkg.contents).toBe(path.normalize("/root/path/to/package"));
+    });
+  });
+
+  describe("set .contents", () => {
+    it("sets pkg.contents to joined value", () => {
+      const pkg = factory({ version: "1.0.0" });
+      pkg.contents = "dist";
+      expect(pkg.contents).toBe(path.normalize("/root/path/to/package/dist"));
+    });
+  });
+
   describe("get .bin", () => {
     it("should return the bin object", () => {
       const pkg = factory({

core/package/index.js

@@ -95,6 +95,27 @@ class Package {
     this[PKG].version = version;
   }
 
+  get contents() {
+    // if modified with setter, use that value
+    if (this._contents) {
+      return this._contents;
+    }
+
+    // if provided by pkg.publishConfig.directory value
+    if (this[PKG].publishConfig && this[PKG].publishConfig.directory) {
+      return path.join(this.location, this[PKG].publishConfig.directory);
+    }
+
+    // default to package root
+    return this.location;
+  }
+
+  set contents(subDirectory) {
+    Object.defineProperty(this, "_contents", {
+      value: path.join(this.location, subDirectory),
+    });
+  }
+
   // "live" collections
   get dependencies() {
     return this[PKG].dependencies;