add nbt builder (#48)

* add nbt builder

* Update README.md

* Update ci.yml

* change how builder is exported + fix typings

Author: u9g

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x]
+        node-version: [14.x]
 
     steps:
     - uses: actions/checkout@v2
@@ -22,4 +22,4 @@ jobs:
       with:
         node-version: ${{ matrix.node-version }}
     - run: npm install
-    - run: npm test
+    - run: npm test

README.md

@@ -84,3 +84,19 @@ Provide the big-endian protodef instance used to parse and serialize nbt.
 ### protoLE
 
 Provide the little-endian protodef instance used to parse and serialize little endian nbt.
+
+### builder
+
+Provides a way to build complex nbt structures simply:
+
+```js
+const nbt = require('prismarine-nbt')
+writePlayerNbt({
+  Air: nbt.short(300),
+  Armor: nbt.list(
+    nbt.comp({ Count: nbt.byte(0), Damage: nbt.short(0), Name: nbt.string("") }),
+    nbt.comp({ Count: nbt.byte(0), Damage: nbt.short(0), Name: nbt.string("") }),
+    nbt.comp({ Count: nbt.byte(0), Damage: nbt.short(0), Name: nbt.string("") }),
+  ),
+})
+```

nbt.js

@@ -155,6 +155,18 @@ function simplify (data) {
   return transform(data.value, data.type)
 }
 
+const builder = {
+  short (value) { return { type: 'short', value } },
+  byte (value) { return { type: 'byte', value } },
+  string (value) { return { type: 'string', value } },
+  comp (value) { return { type: 'compound', value } },
+  int (value) { return { type: 'int', value } },
+  list (...value) {
+    const type = value[0]?.type ?? 'end'
+    return { type: 'list', value: { type, value } }
+  }
+}
+
 module.exports = {
   writeUncompressed,
   parseUncompressed,
@@ -164,5 +176,6 @@ module.exports = {
   parseAs,
   proto: protoBE,
   protoLE,
-  protos
+  protos,
+  ...builder
 }

sample/builderExample.js

@@ -0,0 +1,11 @@
+const nbt = require('prismarine-nbt')
+
+const writePlayerNbt = () => {}
+writePlayerNbt({
+  Air: nbt.short(300),
+  Armor: nbt.list(
+    nbt.comp({ Count: nbt.byte(0), Damage: nbt.short(0), Name: nbt.string('') }),
+    nbt.comp({ Count: nbt.byte(0), Damage: nbt.short(0), Name: nbt.string('') }),
+    nbt.comp({ Count: nbt.byte(0), Damage: nbt.short(0), Name: nbt.string('') })
+  )
+})

typings/index.d.ts

@@ -65,4 +65,11 @@ declare module 'prismarine-nbt'{
   export function parse(data: Buffer, nbtType: NBTFormat, callback: (err: Error | null, value: NBT) => any): void;
   /** @deprecated */
   export function parse(data: Buffer, callback: (err: Error | null, value: NBT) => any): void;
+  
+  export function short<T extends number> (val: T): { type: 'short', value: T }
+  export function byte<T extends number> (val: T): { type: 'byte', value: T }
+  export function string<T extends string> (val: T): { type: 'string', value: T }
+  export function comp<T extends object> (val: T): { type: 'compound', value: T }
+  export function int<T extends number> (val: T): { type: 'int', value: T }
+  export function list<T extends string, K extends {type: T}>(...value: K[]): { type: 'list'; value: { type: T | 'end', value: K[] } };
 }