From 29bd9bfa72bfda2ca5293bee5cce46b409fe0fb1 Mon Sep 17 00:00:00 2001
From: Vasilis Dragon <vasilis@vasilis.club>
Date: Fri, 12 Jun 2026 11:20:30 -0500
Subject: [PATCH] loader: pass tags through to mcData

lib/loader.js returns a fixed object, so the tags key emitted by
dataPaths-driven data.js getters never reached mcData even once tags
data exists in the submodule (minecraft-data#1080). Add the passthrough
plus typings, docs, and a per-version shape contract test.

With the current submodule pin no version has tags data, so mcData.tags
is undefined everywhere: this is inert now and activates on the first
submodule bump after minecraft-data#1080 and its schema land.

Resolves #315. Loader half of the plan discussed in minecraft-data#412.
---
 doc/api.md                  | 13 +++++++++++++
 lib/loader.js               |  4 +++-
 test/load.js                | 23 +++++++++++++++++++++++
 typings/index-template.d.ts |  5 +++++
 typings/test-typings.ts     |  1 +
 5 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/doc/api.md b/doc/api.md
index c186a7c0..ca2c4713 100644
--- a/doc/api.md
+++ b/doc/api.md
@@ -226,6 +226,19 @@ console.log(mcData.materials['mineable/axe'])
 // Returns: { '702': 2, '707': 4, '712': 12, '717': 6, '722': 8, '727': 9 }
 ```
 
+## Tags
+
+### mcData.tags
+
+Registry tags indexed by registry kind (`block`, `item`, `fluid`, `entity_type`), then by namespaced tag name. Tag members are entry names with nested `#tag` references already flattened. `undefined` for versions without tags data.
+
+Example:
+
+```js
+console.log(mcData.tags.block['minecraft:mineable/pickaxe'])
+// Returns: [ 'minecraft:stone', 'minecraft:granite', ... ]
+```
+
 ## Entities
 
 ### mcData.mobs
diff --git a/lib/loader.js b/lib/loader.js
index e8771668..88207ec1 100644
--- a/lib/loader.js
+++ b/lib/loader.js
@@ -85,6 +85,8 @@ function mcDataToNode (mcData) {
 
     sounds: indexes.soundsById,
     soundsByName: indexes.soundsByName,
-    soundsArray: mcData.sounds
+    soundsArray: mcData.sounds,
+
+    tags: mcData.tags
   }
 }
diff --git a/test/load.js b/test/load.js
index 21209518..a1a4ea2f 100644
--- a/test/load.js
+++ b/test/load.js
@@ -54,6 +54,29 @@ describe('versions with block data have block state IDs', () => {
   })
 })
 
+describe('versions with tags data expose them as registry->tag->members', () => {
+  const mcData = require('minecraft-data')
+  const versions = require('minecraft-data').versions
+  let withTags = 0
+  for (const type in versions) {
+    for (const version of versions[type]) {
+      it(type + ' ' + version.minecraftVersion, () => {
+        const data = mcData(type + '_' + version.minecraftVersion)
+        if (!data || data.tags === undefined) return
+        withTags++
+        for (const registry in data.tags) {
+          for (const tag in data.tags[registry]) {
+            assert.ok(Array.isArray(data.tags[registry][tag]), `${registry} ${tag} should map to an array`)
+          }
+        }
+      })
+    }
+  }
+  after(() => {
+    console.log(withTags, 'versions with tags data')
+  })
+})
+
 describe('supportFeature', () => {
   it('dimensionIsAnInt is only accessible in 1.8 - 1.15.2', () => {
     const mcData1Dot9 = require('minecraft-data')('1.9')
diff --git a/typings/index-template.d.ts b/typings/index-template.d.ts
index 1a3bfd84..ee633930 100644
--- a/typings/index-template.d.ts
+++ b/typings/index-template.d.ts
@@ -144,6 +144,11 @@ export interface IndexedData {
 
   materials: { [name: string]: Material }
 
+  /**
+   * Registry tags keyed by registry kind (block, item, fluid, entity_type), then by namespaced tag name. undefined for versions without tags data
+   */
+  tags?: { [registry: string]: { [tagName: string]: string[] } }
+
   mobs: { [id: number]: Entity }
   objects: { [id: number]: Entity }
   entities: { [id: number]: Entity }
diff --git a/typings/test-typings.ts b/typings/test-typings.ts
index bca02f6f..ebd9e8b0 100644
--- a/typings/test-typings.ts
+++ b/typings/test-typings.ts
@@ -5,6 +5,7 @@ console.log(mcData.blocksByName['stone'])
 console.log(mcData.windows['minecraft:brewing_stand'])
 console.log(mcData.version)
 console.log(mcData.effectsByName['Haste'])
+console.log(mcData.tags?.block['minecraft:mineable/pickaxe'])
 
 console.log(mcData.mobs[62])
 console.log(mcData.objects[62])