Gradle script to enforce dependencies order

Signed-off-by: Aayush Gupta <aayushgupta219@gmail.com>

app/build.gradle.kts

@@ -12,6 +12,8 @@ plugins {
     checkstyle
 }
 
+apply(from = "check-dependencies.gradle.kts")
+
 val gitWorkingBranch = providers.exec {
     commandLine("git", "rev-parse", "--abbrev-ref", "HEAD")
 }.standardOutput.asText.map { it.trim() }
@@ -180,7 +182,7 @@ afterEvaluate {
         if (!System.getProperties().containsKey("skipFormatKtlint")) {
             dependsOn("formatKtlint")
         }
-        dependsOn("runCheckstyle", "runKtlint")
+        dependsOn("runCheckstyle", "runKtlint", "checkDependenciesOrder")
     }
 }
 

app/check-dependencies.gradle.kts

@@ -0,0 +1,59 @@
+/*
+ * SPDX-FileCopyrightText: 2024 NewPipe contributors <https://newpipe.net>
+ * SPDX-FileCopyrightText: 2025 NewPipe e.V. <https://newpipe-ev.de>
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+tasks.register("checkDependenciesOrder") {
+    group = "verification"
+    description = "Checks that each section in libs.versions.toml is sorted alphabetically"
+
+    val tomlFile = file("../gradle/libs.versions.toml")
+
+    doLast {
+        if (!tomlFile.exists()) {
+            throw GradleException("TOML file not found")
+        }
+
+        val lines = tomlFile.readLines()
+        val nonSortedBlocks = mutableListOf<List<String>>()
+        var currentBlock = mutableListOf<String>()
+        var prevLine = ""
+        var prevIndex = 0
+
+        lines.forEachIndexed { lineIndex, line ->
+            if (line.trim().isNotEmpty() && !line.startsWith("#")) {
+                if (line.startsWith("[")) {
+                    prevLine = ""
+                } else {
+                    val currIndex = lineIndex + 1
+                    if (prevLine > line) {
+                        if (currentBlock.isNotEmpty() && currentBlock.last() == "$prevIndex: $prevLine") {
+                            currentBlock.add("$currIndex: $line")
+                        } else {
+                            if (currentBlock.isNotEmpty()) {
+                                nonSortedBlocks.add(currentBlock)
+                                currentBlock = mutableListOf()
+                            }
+                            currentBlock.add("$prevIndex: $prevLine")
+                            currentBlock.add("$currIndex: $line")
+                        }
+                    }
+                    prevLine = line
+                    prevIndex = lineIndex + 1
+                }
+            }
+        }
+
+        if (currentBlock.isNotEmpty()) {
+            nonSortedBlocks.add(currentBlock)
+        }
+
+        if (nonSortedBlocks.isNotEmpty()) {
+            throw GradleException(
+                "The following lines were not sorted:\n" +
+                        nonSortedBlocks.joinToString("\n\n") { it.joinToString("\n") }
+            )
+        }
+    }
+}