feat: Allow fetching Git metadata from submodules

.gitignore

@@ -1,3 +1,2 @@
 node_modules
-/gatsby-node.js
 coverage

gatsby-node.js

@@ -0,0 +1,89 @@
+"use strict";
+
+const git = require(`simple-git/promise`);
+
+const path = require('path');
+
+const fs = require('fs');
+
+async function getLogWithRetry(gitRepo, node, retry = 2) {
+  // Need retry, see https://github.com/steveukx/git-js/issues/302
+  // Check again after v2 is released?
+  const filePath = fs.realpathSync.native(node.absolutePath, (error, resolvedPath) => {
+    if (error) {
+      console.log(error);
+      return;
+    } else {
+      return resolvedPath;
+    }
+  });
+  const logOptions = {
+    file: filePath,
+    n: 1,
+    format: {
+      date: `%ai`,
+      authorName: `%an`,
+      authorEmail: "%ae"
+    }
+  };
+  const log = await gitRepo.log(logOptions);
+
+  if (!log.latest && retry > 0) {
+    return getLogWithRetry(gitRepo, node, retry - 1);
+  }
+
+  return log;
+}
+
+async function onCreateNode({
+  node,
+  actions
+}, pluginOptions) {
+  const {
+    createNodeField
+  } = actions;
+
+  if (node.internal.type !== `File`) {
+    return;
+  }
+
+  if (pluginOptions.include && !pluginOptions.include.test(node.absolutePath)) {
+    return;
+  }
+
+  if (pluginOptions.ignore && pluginOptions.ignore.test(node.absolutePath)) {
+    return;
+  }
+
+  const gitRepo = git(pluginOptions.dir || fs.realpathSync.native(path.dirname(node.absolutePath), (error, resolvedPath) => {
+    if (error) {
+      console.log(error);
+      return;
+    } else {
+      return resolvedPath;
+    }
+  }));
+  const log = await getLogWithRetry(gitRepo, node);
+
+  if (!log.latest) {
+    return;
+  }
+
+  createNodeField({
+    node,
+    name: `gitLogLatestAuthorName`,
+    value: log.latest.authorName
+  });
+  createNodeField({
+    node,
+    name: `gitLogLatestAuthorEmail`,
+    value: log.latest.authorEmail
+  });
+  createNodeField({
+    node,
+    name: `gitLogLatestDate`,
+    value: log.latest.date
+  });
+}
+
+exports.onCreateNode = onCreateNode;

src/__tests__/gatsby_node.js

@@ -11,6 +11,7 @@ let actions;
 let node;
 let createNodeSpec;
 let dummyRepoPath;
+let dummyRepoSubmodulePath;
 
 beforeEach(() => {
   createNodeField = jest.fn();
@@ -33,6 +34,17 @@ beforeEach(() => {
   };
 });
 
+const initGitRepo = async (path, username, useremail, remote) => {
+  const gitRepo = git(path);
+
+  await gitRepo.init();
+  await gitRepo.addConfig("user.name", username);
+  await gitRepo.addConfig("user.email", useremail);
+  await gitRepo.addRemote("origin", remote);
+
+  return gitRepo;
+}
+
 describe(`Processing nodes not matching initial filtering`, () => {
   it(`should not add any field when internal type is not 'File'`, async () => {
     node.internal.type = "Other";
@@ -69,19 +81,45 @@ describe(`Processing File nodes matching filter regex`, () => {
       path.join(os.tmpdir(), "gatsby-transform-gitinfo-")
     );
 
-    const gitRepo = git(dummyRepoPath);
-    await gitRepo.init();
-    await gitRepo.addConfig("user.name", "Some One");
-    await gitRepo.addConfig("user.email", "[email protected]");
-    await gitRepo.addRemote("origin", "https://some.git.repo");
+    const gitRepo = await initGitRepo(
+      dummyRepoPath,
+      "Some One",
+      "[email protected]",
+      "https://some.git.repo",
+    );
 
     fs.writeFileSync(`${dummyRepoPath}/README.md`, "Hello");
     await gitRepo.add("README.md");
-    await gitRepo.commit("Add README", "README.md", {
-      "--date": '"Mon 20 Aug 2018 20:19:19 UTC"'
-    });
+    await gitRepo.commit(
+      "Add README",
+      "README.md", {
+        "--date": '"Mon 20 Aug 2018 20:19:19 UTC"'
+      }
+    );
 
     fs.writeFileSync(`${dummyRepoPath}/unversionned`, "World");
+
+    dummyRepoSubmodulePath = fs.mkdtempSync(
+      path.join(os.tmpdir(), "gatsby-transform-gitinfo-submodule-")
+    );
+
+    const gitRepoSubmodule = await initGitRepo(
+      dummyRepoSubmodulePath,
+      "Some One Else",
+      "[email protected]",
+      "https://some.other.git.repo",
+    );
+
+    fs.writeFileSync(`${dummyRepoSubmodulePath}/CONTENT.md`, "Hello");
+    await gitRepoSubmodule.add("CONTENT.md");
+    await gitRepoSubmodule.commit(
+      "Add CONTENT",
+      "CONTENT.md", {
+        "--date": '"Mon 20 Aug 2018 20:19:19 UTC"'
+      }
+    );
+
+    await gitRepo.submoduleAdd(dummyRepoSubmodulePath, "submodule")
   });
 
   it("should add log and remote git info to commited File node", async () => {
@@ -109,6 +147,31 @@ describe(`Processing File nodes matching filter regex`, () => {
     });
   });
 
+  it("should add log and remote git info to file in submodule", async () => {
+    node.absolutePath = `${dummyRepoPath}/submodule/CONTENT.md`;
+    node.dir = dummyRepoPath;
+    await onCreateNode(createNodeSpec, {
+      include: /md/,
+      dir: dummyRepoPath
+    });
+    expect(createNodeField).toHaveBeenCalledTimes(3);
+    expect(createNodeField).toHaveBeenCalledWith({
+      node,
+      name: `gitLogLatestAuthorName`,
+      value: `Some One Else`
+    });
+    expect(createNodeField).toHaveBeenCalledWith({
+      node,
+      name: `gitLogLatestAuthorEmail`,
+      value: `[email protected]`
+    });
+    expect(createNodeField).toHaveBeenCalledWith({
+      node,
+      name: `gitLogLatestDate`,
+      value: `2018-08-20 20:19:19 +0000`
+    });
+  });
+
   it("should not add log or remote git info to unversionned File node", async () => {
     node.absolutePath = `${dummyRepoPath}/unversionned`;
     node.dir = dummyRepoPath;

src/gatsby-node.js

@@ -1,11 +1,23 @@
 const git = require(`simple-git/promise`);
+const path = require('path');
+const fs = require('fs')
 
 async function getLogWithRetry(gitRepo, node, retry = 2) {
   // Need retry, see https://github.com/steveukx/git-js/issues/302
   // Check again after v2 is released?
 
+  const filePath = fs.realpathSync.native(node.absolutePath, (error, resolvedPath) => {
+    if (error) {
+      console.log(error)
+      return
+    }
+    else {
+      return resolvedPath
+    }
+  });
+
   const logOptions = {
-    file: node.absolutePath,
+    file: filePath,
     n: 1,
     format: {
       date: `%ai`,
@@ -36,7 +48,15 @@ async function onCreateNode({ node, actions }, pluginOptions) {
     return;
   }
 
-  const gitRepo = git(pluginOptions.dir);
+  const gitRepo = git(pluginOptions.dir || fs.realpathSync.native(path.dirname(node.absolutePath), (error, resolvedPath) => {
+    if (error) {
+      console.log(error)
+      return
+    }
+    else {
+      return resolvedPath
+    }
+  }));
   const log = await getLogWithRetry(gitRepo, node);
 
   if (!log.latest) {