feat(publish): Add --git-head option to preserve gitless `from-pack…

…age` metadata

Fixes #1933

commands/publish/README.md

@@ -46,6 +46,7 @@ This is useful when a previous `lerna publish` failed to publish all packages to
 - [`--canary`](#--canary)
 - [`--contents <dir>`](#--contents-dir)
 - [`--dist-tag <tag>`](#--dist-tag-tag)
+- [`--git-head <sha>`](#--git-head-sha)
 - [`--no-git-reset`](#--no-git-reset)
 - [`--no-verify-access`](#--no-verify-access)
 - [`--preid`](#--preid)
@@ -103,6 +104,19 @@ This option can be used to publish a [`prerelease`](http://carrot.is/coding/npm_
 > Note: the `latest` tag is the one that is used when a user runs `npm install my-package`.
 > To install a different tag, a user can run `npm install my-package@prerelease`.
 
+### `--git-head <sha>`
+
+Explicit SHA to set as [`gitHead`](https://git.io/fh7np) on manifests when packing tarballs, only allowed with [`from-package`](#bump-from-package) positional.
+
+For example, when publishing from AWS CodeBuild (where `git` is not available),
+you could use this option to pass the appropriate [environment variable](https://docs.aws.amazon.com/codebuild/latest/userguide/build-env-ref-env-vars.html) to use for this package metadata:
+
+```sh
+lerna publish from-package --git-head ${CODEBUILD_RESOLVED_SOURCE_VERSION}
+```
+
+Under all other circumstances, this value is derived from a local `git` command.
+
 ### `--no-git-reset`
 
 By default, `lerna publish` ensures any changes to the working tree have been reset.

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

@@ -353,6 +353,18 @@ test("publish --canary with dirty tree throws error", async () => {
   expect.assertions(1);
 });
 
+test("publish --canary --git-head <sha> throws an error", async () => {
+  const cwd = await initFixture("normal");
+
+  try {
+    await lernaPublish(cwd)("--canary", "--git-head", "deadbeef");
+  } catch (err) {
+    expect(err.prefix).toBe("EGITHEAD");
+  }
+
+  expect.hasAssertions();
+});
+
 test("publish --canary --include-merged-tags calls git describe correctly", async () => {
   const spy = jest.spyOn(childProcess, "exec");
   const cwd = await initTaggedFixture("normal");

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

@@ -68,6 +68,16 @@ describe("PublishCommand", () => {
 
       expect.assertions(2);
     });
+
+    it("errors when --git-head is passed without from-package positional", async () => {
+      try {
+        await lernaPublish(cwd)("--git-head", "deadbeef");
+      } catch (err) {
+        expect(err.message).toBe("--git-head is only allowed with 'from-package' positional");
+      }
+
+      expect.hasAssertions();
+    });
   });
 
   describe("with implied versioning", () => {

commands/publish/__tests__/publish-from-git.test.js

@@ -108,4 +108,16 @@ describe("publish from-git", () => {
 
     expect.assertions(1);
   });
+
+  it("throws an error when --git-head is passed", async () => {
+    const cwd = await initFixture("normal");
+
+    try {
+      await lernaPublish(cwd)("from-git", "--git-head", "deadbeef");
+    } catch (err) {
+      expect(err.prefix).toBe("EGITHEAD");
+    }
+
+    expect.hasAssertions();
+  });
 });

commands/publish/__tests__/publish-from-package.test.js

@@ -112,4 +112,15 @@ describe("publish from-package", () => {
     );
     expect(logMessages).toContain("Unable to reset working tree changes, this probably isn't a git repo.");
   });
+
+  it("accepts --git-head override", async () => {
+    getUnpublishedPackages.mockImplementationOnce(packageGraph => [packageGraph.get("package-1")]);
+
+    const cwd = await initFixture("independent");
+
+    await lernaPublish(cwd)("from-package", "--git-head", "deadbeef");
+
+    expect(npmPublish).toHaveBeenCalled();
+    expect(writePkg.updatedManifest("package-1").gitHead).toBe("deadbeef");
+  });
 });

commands/publish/command.js

@@ -35,6 +35,12 @@ exports.builder = yargs => {
       type: "string",
       requiresArg: true,
     },
+    "git-head": {
+      describe:
+        "Explicit SHA to set as gitHead when packing tarballs, only allowed with 'from-package' positional.",
+      type: "string",
+      requiresArg: true,
+    },
     registry: {
       describe: "Use the specified registry for all npm client operations.",
       type: "string",

commands/publish/index.js

@@ -10,6 +10,7 @@ const pReduce = require("p-reduce");
 const semver = require("semver");
 
 const Command = require("@lerna/command");
+const ValidationError = require("@lerna/validation-error");
 const describeRef = require("@lerna/describe-ref");
 const checkWorkingTree = require("@lerna/check-working-tree");
 const PromptUtilities = require("@lerna/prompt");
@@ -70,6 +71,10 @@ class PublishCommand extends Command {
       this.logger.info("require-scripts", "enabled");
     }
 
+    if (this.requiresGit && this.options.gitHead) {
+      throw new ValidationError("EGITHEAD", "--git-head is only allowed with 'from-package' positional");
+    }
+
     // https://docs.npmjs.com/misc/config#save-prefix
     this.savePrefix = this.options.exact ? "" : "^";
 
@@ -492,7 +497,7 @@ class PublishCommand extends Command {
 
   annotateGitHead() {
     try {
-      const gitHead = getCurrentSHA(this.execOpts);
+      const gitHead = this.options.gitHead || getCurrentSHA(this.execOpts);
 
       for (const pkg of this.packagesToPublish) {
         // provide gitHead property that is normally added during npm publish