Automatically publish prereleases to npm (#155)

This commit creates `x.x.x-insiders.COMMIT_HASH` builds of all of our public packages, and publishes them to npm with the `insiders` tag, so one could say `npm install @theatre/core@0.4.8-insiders.bsdf387` and use the package at that particular commit.

Co-authored-by: Aria Minaei <aria.minaei@gmail.com>

scripts/prerelease.mjs

@@ -0,0 +1,149 @@
+/**
+ * This script publishes the insider packages from the CI. You can't run it locally unless you have a a valid npm access token and you store its value in the `NPM_TOKEN` environmental variable.
+ */
+
+import os from 'os'
+import path from 'path'
+
+const packagesToPublish = [
+  '@theatre/core',
+  '@theatre/studio',
+  '@theatre/dataverse',
+  '@theatre/react',
+  '@theatre/browser-bundles',
+  '@theatre/r3f',
+]
+
+/**
+ * Receives a version number and returns it without the tags, if there are any
+ *
+ * @param {string} version - Version number
+ * @returns Version number without the tags
+ *
+ * @example
+ * ```javascript
+ * const version_1 = '0.4.8-dev3-ec175817'
+ * const version_2 = '0.4.8'
+ *
+ * stripTag(version_1) === stripTag(version_2) === '0.4.8' // returns `true`
+ * ```
+ */
+function stripTag(version) {
+  const regExp = /^[0-9]+\.[0-9]+\.[0-9]+/g
+  const matches = version.match(regExp)
+  if (!matches) {
+    throw new Error(`Version number not found in "${version}"`)
+  }
+
+  return matches[0]
+}
+
+/**
+ * Creates a version number like `0.4.8-insiders.ec175817`
+ *
+ * @param {string} packageName - Name of the package
+ * @param {string} commitHash - A commit hash
+ */
+function getNewVersionName(packageName, commitHash) {
+  // The `r3f` package has its own release schedule, so its version numbers
+  // are almost always different from the rest of the packages.
+  const pathToPackageJson =
+    packageName === '@theatre/r3f'
+      ? path.resolve(__dirname, '..', 'packages', 'r3f', 'package.json')
+      : path.resolve(__dirname, '../', './package.json')
+
+  const jsonData = JSON.parse(
+    fs.readFileSync(pathToPackageJson, {encoding: 'utf-8'}),
+  )
+  const strippedVersion = stripTag(jsonData.version)
+
+  return `${strippedVersion}-insiders.${commitHash}`
+}
+
+/**
+ * Assigns the new versions to the packages
+ *
+ * @param {{name: string, location: string}[]} workspacesListObjects - An Array of objects containing information about the workspaces
+ * @param {string} latestCommitHash - Hash of the latest commit
+ */
+async function assignVersions(workspacesListObjects, latestCommitHash) {
+  for (const workspaceData of workspacesListObjects) {
+    const pathToPackage = path.resolve(
+      __dirname,
+      '../',
+      workspaceData.location,
+      './package.json',
+    )
+
+    const original = JSON.parse(
+      fs.readFileSync(pathToPackage, {encoding: 'utf-8'}),
+    )
+
+    let {version, dependencies, peerDependencies, devDependencies} = original
+    // The @theatre/r3f package curently doesn't track the same version number of the other packages like @theatre/core,
+    // so we need to generate version numbers independently for each package
+    version = getNewVersionName(workspaceData.name, latestCommitHash)
+    // Normally we don't have to override the package versions in dependencies because yarn would already convert
+    // all the "workspace:*" versions to a fixed version before publishing. However, packages like @theatre/studio
+    // have a peerDependency on @theatre/core set to "*" (meaning they would work with any version of @theatre/core).
+    // This is not the desired behavior in pre-release versions, so here, we'll fix those "*" versions to the set version.
+    for (const deps of [dependencies, peerDependencies, devDependencies]) {
+      if (!deps) continue
+      for (const wpObject of workspacesListObjects) {
+        if (deps[wpObject.name]) {
+          deps[wpObject.name] = getNewVersionName(
+            wpObject.name,
+            latestCommitHash,
+          )
+        }
+      }
+    }
+    const newJson = {
+      ...original,
+      version,
+      dependencies,
+      peerDependencies,
+      devDependencies,
+    }
+    fs.writeFileSync(
+      path.join(pathToPackage),
+      JSON.stringify(newJson, undefined, 2),
+      {encoding: 'utf-8'},
+    )
+    await $`prettier --write ${workspaceData.location + '/package.json'}`
+  }
+}
+
+;(async function () {
+  // @ts-ignore ignore
+  process.env.THEATRE_IS_PUBLISHING = true
+  // In the CI `git log -1` points to a fake merge commit,
+  // so we have to use the value of a special GitHub context variable
+  // through the `GITHUB_SHA` environmental variable.
+
+  // The length of the abbreviated commit hash can change, that's why we
+  // need the lenght of the fake merge commit's abbreviated hash.
+  const fakeMergeCommitHashLength = (await $`git log -1 --pretty=format:%h`)
+    .stdout.length
+
+  const latestCommitHash = process.env.GITHUB_SHA.slice(
+    0,
+    fakeMergeCommitHashLength,
+  )
+
+  const workspacesListString = await $`yarn workspaces list --json`
+  const workspacesListObjects = workspacesListString.stdout
+    .split(os.EOL)
+    // strip out empty lines
+    .filter(Boolean)
+    .map((x) => JSON.parse(x))
+
+  await assignVersions(workspacesListObjects, latestCommitHash)
+
+  await Promise.all(
+    packagesToPublish.map((workspaceName) => {
+      const npmTag = 'insiders'
+      return $`yarn workspace ${workspaceName} npm publish --access public --tag ${npmTag}`
+    }),
+  )
+})()