Implement GradleProjectFlattenerCli

src/main/kotlin/slack/cli/gradle/GradleProjectFlattener.kt

@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2023 Slack Technologies, LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package slack.cli.gradle
+
+import com.github.ajalt.clikt.core.CliktCommand
+import com.github.ajalt.clikt.parameters.options.default
+import com.github.ajalt.clikt.parameters.options.defaultLazy
+import com.github.ajalt.clikt.parameters.options.option
+import com.github.ajalt.clikt.parameters.types.path
+import java.io.File
+import kotlin.io.path.ExperimentalPathApi
+import kotlin.io.path.appendLines
+import kotlin.io.path.appendText
+import kotlin.io.path.copyToRecursively
+import kotlin.io.path.exists
+import kotlin.io.path.isDirectory
+import kotlin.io.path.readText
+import kotlin.io.path.relativeTo
+import slack.cli.dryRunOption
+import slack.cli.projectDirOption
+
+/**
+ * A CLI that flattens all gradle projects in a given directory to be top level while preserving
+ * their original project paths.
+ *
+ * This is useful for flattening nested projects that use Dokka, which does not currently support
+ * easy doc gen for nested projects and end up with colliding names.
+ *
+ * It's recommended to run `./gradlew clean` first before running this script to minimize work.
+ */
+public class GradleProjectFlattenerCli :
+  CliktCommand(
+    help =
+      "A CLI that flattens all gradle projects in a given directory to be top level while preserving their original project paths."
+  ) {
+
+  private val projectDir by projectDirOption()
+
+  private val settingsFile by
+    option(
+        "--settings-file",
+        "-s",
+        help =
+          "The settings.gradle file to use. Defaults to settings.gradle.kts in the current directory. Note this file _must_ only have a single, top-level `include()` call with vararg project args."
+      )
+      .path(mustExist = true, canBeDir = false)
+      .defaultLazy { projectDir.resolve("settings.gradle.kts") }
+
+  private val projectDelimiter: String by option().default("--")
+
+  private val dryRun by dryRunOption()
+
+  @ExperimentalPathApi
+  override fun run() {
+    val projectPaths =
+      settingsFile.readText().trim().removePrefix("include(").removeSuffix(")").split(",").map {
+        it.trim().removeSurrounding("\"")
+      }
+
+    val newPathMapping = mutableMapOf<String, String>()
+    for (path in projectPaths) {
+      val realPath = projectDir.resolve(path.removePrefix(":").replace(":", File.separator))
+      check(realPath.exists()) { "Expected $realPath to exist." }
+      check(realPath.isDirectory()) { "Expected $realPath to be a directory." }
+      val newPath = projectDir.resolve(path.removePrefix(":").replace(":", projectDelimiter))
+      if (newPath == realPath) {
+        // Already top-level, move on
+        continue
+      }
+      newPathMapping[path] = newPath.relativeTo(projectDir).toString()
+      echo("Flattening $realPath to $newPath")
+      if (!dryRun) {
+        realPath.copyToRecursively(newPath, followLinks = false, overwrite = false)
+      }
+    }
+
+    echo("Finished flattening projects. Updating settings file")
+    val newPaths =
+      projectPaths.mapNotNull { path ->
+        // Point at their new paths
+        // Example:
+        //   project(":libraries:compose-extensions:pull-refresh").projectDir =
+        //     file("libraries--compose-extensions--pull-refresh")
+        val newPath = newPathMapping[path] ?: return@mapNotNull null
+        "project(\"$path\").projectDir = file(\"$newPath\")".also { echo("+  $it") }
+      }
+
+    if (!dryRun) {
+      settingsFile.appendText("\n\n")
+      settingsFile.appendLines(newPaths)
+    }
+  }
+}