Add version regression test and fix data path inconsistencies (#1086)

* Initial plan

* Add version regression test with snapshot handling

Co-authored-by: extremeheat <13713600+extremeheat@users.noreply.github.com>

* Complete working version regression test implementation

Co-authored-by: extremeheat <13713600+extremeheat@users.noreply.github.com>

* Simplify version regression test using versions.json ordering

Co-authored-by: extremeheat <13713600+extremeheat@users.noreply.github.com>

* Simplify test logic and fix data path regressions per review feedback

Co-authored-by: extremeheat <13713600+extremeheat@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: extremeheat <13713600+extremeheat@users.noreply.github.com>

Author: Copilot

data/dataPaths.json

@@ -1475,7 +1475,7 @@
       "mapIcons": "pc/1.20.2",
       "commands": "pc/1.20.3",
       "sounds": "pc/1.21.1",
-      "proto": "pc/1.21.3"
+      "proto": "pc/1.21.1"
     },
     "1.21.1": {
       "attributes": "pc/1.21.1",
@@ -2441,11 +2441,11 @@
       "language": "bedrock/1.20.10"
     },
     "1.21.50": {
-      "blocks": "bedrock/1.21.0",
+      "blocks": "bedrock/1.21.42",
       "blockStates": "bedrock/1.21.50",
-      "blockCollisionShapes": "bedrock/1.21.0",
+      "blockCollisionShapes": "bedrock/1.21.42",
       "biomes": "bedrock/1.20.0",
-      "entities": "bedrock/1.21.0",
+      "entities": "bedrock/1.21.42",
       "items": "bedrock/1.21.0",
       "recipes": "bedrock/1.19.10",
       "instruments": "bedrock/1.17.0",
@@ -2455,8 +2455,8 @@
       "protocol": "bedrock/1.21.50",
       "windows": "bedrock/1.16.201",
       "steve": "bedrock/1.21.50",
-      "blocksB2J": "bedrock/1.21.0",
-      "blocksJ2B": "bedrock/1.21.0",
+      "blocksB2J": "bedrock/1.21.42",
+      "blocksJ2B": "bedrock/1.21.42",
       "proto": "bedrock/1.21.50",
       "types": "bedrock/1.21.50",
       "version": "bedrock/1.21.50",

tools/js/test/audit_version_regression.js

@@ -0,0 +1,95 @@
+/* eslint-env mocha */
+
+const assert = require('assert')
+
+/**
+ * Gets the chronological index of a version from the versions.json file
+ * Returns -1 if version is not found, or null for non-version strings like "latest"
+ */
+function getVersionIndex (platform, version) {
+  // Skip non-version entries like "latest"
+  if (version === 'latest') return null
+
+  try {
+    const versions = require(`../../../data/${platform}/common/versions.json`)
+    return versions.indexOf(version)
+  } catch (error) {
+    return -1
+  }
+}
+
+describe('audit version regression in dataPaths', function () {
+  const dataPaths = require('../../../data/dataPaths.json')
+
+  const platforms = ['pc', 'bedrock']
+
+  platforms.forEach(function (platform) {
+    if (!dataPaths[platform]) return
+
+    describe(`${platform} version regression`, function () {
+      it('should not have newer versions pointing to older data than previously seen', function () {
+        const platformData = dataPaths[platform]
+
+        // Load the chronological version order from versions.json
+        const versions = require(`../../../data/${platform}/common/versions.json`)
+
+        // Track the highest version index seen for each data type
+        const highestVersionIndexForDataType = {}
+
+        // Iterate through versions in chronological order, but only process ones in dataPaths
+        for (const version of versions) {
+          if (!platformData[version]) continue
+
+          const versionData = platformData[version]
+
+          for (const [dataType, dataPath] of Object.entries(versionData)) {
+            // Skip non-version data paths (like "latest" or cross-platform refs)
+            const pathParts = dataPath.split('/')
+            if (pathParts.length !== 2) continue
+
+            const [dataPathPlatform, dataPathVersion] = pathParts
+
+            // Skip cross-platform references (e.g., bedrock data pointing to pc data)
+            if (dataPathPlatform !== platform) continue
+
+            // Get the chronological index of the data path version
+            const dataPathIndex = getVersionIndex(platform, dataPathVersion)
+
+            // Skip if version not found in versions.json (like "latest")
+            if (dataPathIndex === null || dataPathIndex === -1) continue
+
+            // Initialize tracking for this data type if not seen before
+            if (!highestVersionIndexForDataType[dataType]) {
+              highestVersionIndexForDataType[dataType] = {
+                version: dataPath,
+                index: dataPathIndex
+              }
+              continue
+            }
+
+            // Check if current data path is older than the highest we've seen
+            const previousHighest = highestVersionIndexForDataType[dataType]
+            if (dataPathIndex < previousHighest.index) {
+              assert.fail(
+                `Version regression detected in ${platform}:\n` +
+                `  Version: ${version}\n` +
+                `  Data type: ${dataType}\n` +
+                `  Current path: ${dataPath} (index: ${dataPathIndex})\n` +
+                `  Expected at least: ${previousHighest.version} (index: ${previousHighest.index})\n` +
+                '  A newer version should not point to older data than previously seen.'
+              )
+            }
+
+            // Update the highest version if current is newer
+            if (dataPathIndex > previousHighest.index) {
+              highestVersionIndexForDataType[dataType] = {
+                version: dataPath,
+                index: dataPathIndex
+              }
+            }
+          }
+        }
+      })
+    })
+  })
+})