From 66845ba6c2be63ba5039c9697810c31844c38494 Mon Sep 17 00:00:00 2001
From: f4lco <github@falcoduersch.com>
Date: Fri, 8 Nov 2024 22:23:06 +0100
Subject: [PATCH] Reconfigure Jackson to make JSON output stable

---
 .../resources/com/libyear/expectedReport.json | 16 ++++----------
 .../com/libyear/traversal/ReportingVisitor.kt | 21 +++++++++++++++----
 2 files changed, 21 insertions(+), 16 deletions(-)

diff --git a/libyear-gradle-plugin/src/functionalTest/resources/com/libyear/expectedReport.json b/libyear-gradle-plugin/src/functionalTest/resources/com/libyear/expectedReport.json
index ac57429..f19ef68 100644
--- a/libyear-gradle-plugin/src/functionalTest/resources/com/libyear/expectedReport.json
+++ b/libyear-gradle-plugin/src/functionalTest/resources/com/libyear/expectedReport.json
@@ -1,24 +1,16 @@
 {
   "collected" : [ {
     "module" : {
-      "version" : "1.9",
       "group" : "org.apache.commons",
-      "module" : {
-        "group" : "org.apache.commons",
-        "name" : "commons-text"
-      },
-      "name" : "commons-text"
+      "name" : "commons-text",
+      "version" : "1.9"
     },
     "lag_days" : 1361
   }, {
     "module" : {
-      "version" : "4.4",
       "group" : "org.apache.commons",
-      "module" : {
-        "group" : "org.apache.commons",
-        "name" : "commons-collections4"
-      },
-      "name" : "commons-collections4"
+      "name" : "commons-collections4",
+      "version" : "4.4"
     },
     "lag_days" : 1806
   } ],
diff --git a/libyear-gradle-plugin/src/main/kotlin/com/libyear/traversal/ReportingVisitor.kt b/libyear-gradle-plugin/src/main/kotlin/com/libyear/traversal/ReportingVisitor.kt
index a841f9c..6193a72 100644
--- a/libyear-gradle-plugin/src/main/kotlin/com/libyear/traversal/ReportingVisitor.kt
+++ b/libyear-gradle-plugin/src/main/kotlin/com/libyear/traversal/ReportingVisitor.kt
@@ -1,6 +1,8 @@
 package com.libyear.traversal
 
+import com.fasterxml.jackson.databind.MapperFeature
 import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.databind.SerializationFeature
 import com.fasterxml.jackson.module.kotlin.registerKotlinModule
 import com.libyear.sourcing.VersionOracle
 import com.libyear.util.formatApproximate
@@ -85,14 +87,14 @@ class ReportingVisitor(
     val report = mapOf(
       "collected" to collected.map {
         mapOf(
-          "module" to it.module,
+          "module" to ReportModule(it.module),
           "lag_days" to it.lag.toDays()
         )
       },
-      "missing_info" to missingInfo,
-      "errors" to errors
+      "missing_info" to missingInfo.map(::ReportModule),
+      "errors" to errors.map(::ReportModule)
     )
-    val objectMapper = ObjectMapper().registerKotlinModule()
+    val objectMapper = ObjectMapper().registerKotlinModule().configure(MapperFeature.SORT_PROPERTIES_ALPHABETICALLY, true)
     val json = objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(report)
     val reportFile = File(project.buildDir, "reports/libyear/libyear.json")
     reportFile.parentFile.mkdirs()
@@ -106,4 +108,15 @@ class ReportingVisitor(
     ModuleVersionIdentifier::getName,
     ModuleVersionIdentifier::getVersion
   )
+
+  /** JSON-serializable subset of [ModuleVersionIdentifier]. **/
+  data class ReportModule(
+    val group: String,
+    val name: String,
+    val version: String
+  ) {
+
+    constructor(mvi: ModuleVersionIdentifier):
+      this(mvi.group, mvi.name, mvi.version)
+  }
 }