docs: link to next docs and vice versa (#1438)

1 files changed, 54 insertions, 3 deletions

diff --git a/docs/.vitepress/versions.ts b/docs/.vitepress/versions.ts
index c82a5ee0..7d37619d 100644
--- a/docs/.vitepress/versions.ts
+++ b/docs/.vitepress/versions.ts
@@ -1,7 +1,58 @@
+import { execSync } from 'node:child_process';
+import * as semver from 'semver';
 import { version } from '../../package.json';
 
-export const currentVersion = `v${version}`;
+function readBranchName(): string {
+  return (
+    execSync('git branch --show-current').toString('utf8').trim() || 'unknown'
+  );
+}
 
+function readOtherLatestReleaseTagNames(): string[] {
+  const currentMajorVersion = semver.major(version);
+  const latestReleaseTagNames = execSync('git tag -l')
+    .toString('utf8')
+    .split('\n')
+    .filter((tag) => semver.valid(tag))
+    .reduce<Record<number, string[]>>((acc, tag) => {
+      const majorVersion = semver.major(tag);
+      // Only consider tags for our deployed website versions,
+      // excluding the current major version.
+      if (majorVersion >= 6 && majorVersion !== currentMajorVersion) {
+        (acc[majorVersion] = acc[majorVersion] ?? []).push(tag);
+      }
+      return acc;
+    }, {});
+  return Object.entries(latestReleaseTagNames)
+    .map(([major, tags]) => semver.maxSatisfying(tags, `^${major}`))
+    .sort(semver.rcompare);
+}
+
+// Set by netlify
+const {
+  CONTEXT: deployContext = 'local',
+  BRANCH: branchName = readBranchName(),
+} = process.env;
+
+const hiddenLink =
+  deployContext === 'production'
+    ? 'https://fakerjs.dev/'
+    : `https://${branchName}.fakerjs.dev/`;
+const otherVersions = readOtherLatestReleaseTagNames();
+const isReleaseBranch = /^v\d+$/.test(branchName);
+
+export const currentVersion = isReleaseBranch ? `v${version}` : branchName;
 export const oldVersions = [
-  { version: 'v6.3.1', link: 'https://v6.fakerjs.dev/' },
-];
+  {
+    version: 'latest',
+    link: 'https://fakerjs.dev/',
+  },
+  {
+    version: 'next',
+    link: 'https://next.fakerjs.dev/',
+  },
+  ...otherVersions.map((version) => ({
+    version,
+    link: `https://v${semver.major(version)}.fakerjs.dev/`,
+  })),
+].filter(({ link }) => link !== hiddenLink);