feat: add custom inspect behavior for buffers

Author: janvennemann

common/Resources/ti.internal/extensions/node/buffer.js

@@ -14,7 +14,17 @@
  * a Uint8Array in any of our APIs that take a Ti.Buffer and eventually deprecating/removing Ti.Buffer.
  */
 
-import{isInsideNodeModules}from'./internal/util';
+import{
+customInspectSymbol,
+getOwnNonIndexProperties,
+isBuffer,
+isInsideNodeModules,
+propertyFilter
+}from'./internal/util';
+
+import{inspectasutilInspect}from'./internal/util/inspect';
+
+const{ALL_PROPERTIES,ONLY_ENUMERABLE}=propertyFilter;
 
 // https://nodejs.org/api/buffer.html#buffer_buffers_and_character_encodings
 constTI_CODEC_MAP=newMap();
@@ -51,6 +61,8 @@ const uint8DoubleArray = new Uint8Array(doubleArray.buffer);
 constfloatArray=newFloat32Array(1);
 constuint8FloatArray=newUint8Array(floatArray.buffer);
 
+letINSPECT_MAX_BYTES=50;
+
 classBuffer{
 /**
  * Constructs a new buffer.
@@ -80,17 +92,23 @@ class Buffer {
 
 consttiBuffer=arg;
 letstart=encodingOrOffset;
-this._tiBuffer=tiBuffer;
 if(start===undefined){
 start=0;
 }
-this.byteOffset=start;
 if(length===undefined){
-this.length=tiBuffer.length-this.byteOffset;
-}else{
-this.length=length;
+length=tiBuffer.length-start;
 }
-this._isBuffer=true;
+Object.defineProperties(this,{
+byteOffset: {
+value: start
+},
+length: {
+value: length
+},
+_tiBuffer: {
+value: tiBuffer
+}
+});
 // FIXME: Support .buffer property that holds an ArrayBuffer!
 }
 
@@ -1405,10 +1423,46 @@ class Buffer {
  * @returns {boolean}
  */
 staticisBuffer(obj){
-returnobj!==null&&obj!==undefined&&obj._isBuffer===true;
+returnobj!==null&&obj!==undefined&&obj[isBuffer]===true;
+}
+
+// Override how buffers are presented by util.inspect().
+[customInspectSymbol](recurseTimes,ctx){
+constmax=INSPECT_MAX_BYTES;
+constactualMax=Math.min(max,this.length);
+constremaining=this.length-max;
+letstr=this.slice(0,actualMax).toString('hex').replace(/(.{2})/g,'$1 ').trim();
+if(remaining>0){
+str+=` ... ${remaining} more byte${remaining>1 ? 's' : ''}`;
+}
+// Inspect special properties as well, if possible.
+if(ctx){
+letextras=false;
+constfilter=ctx.showHidden ? ALL_PROPERTIES : ONLY_ENUMERABLE;
+constobj=getOwnNonIndexProperties(this,filter).reduce((obj,key)=>{
+extras=true;
+obj[key]=this[key];
+returnobj;
+},Object.create(null));
+if(extras){
+if(this.length!==0){
+str+=', ';
+}
+// '[Object: null prototype] {'.length === 26
+// This is guarded with a test.
+str+=utilInspect(obj,{
+ ...ctx,
+breakLength: Infinity,
+compact: true
+}).slice(27,-2);
+}
+}
+return`<${this.constructor.name}${str}>`;
 }
 }
 
+Buffer.prototype.inspect=Buffer.prototype[customInspectSymbol];
+
 Buffer.poolSize=8192;
 
 exportdefault{
@@ -1543,6 +1597,8 @@ const arrayIndexHandler = {
 if(Number.isSafeInteger(num)){
 returngetAdjustedIndex(target,num);
 }
+}elseif(propKey===isBuffer){
+returntrue;
 }
 returnReflect.get(target,propKey,receiver);
 },
@@ -1589,7 +1645,7 @@ function setAdjustedIndex(buf, index, value) {
  * @returns {Buffer} wrapped inside a Proxy
  */
 functionnewBuffer(...args){
-returnnewProxy(newBuffer(...args),arrayIndexHandler);// eslint-disable-line security/detect-new-buffer
+returnnewProxy(newBuffer(...args),arrayIndexHandler);// eslint-disable-line security/detect-new-buffer
 }
 
 /**

common/Resources/ti.internal/extensions/node/internal/util.js

@@ -3,6 +3,7 @@ import { isNativeError } from './util/types';
 constkNodeModulesRE=/^(.*)[\\/]node_modules[\\/]/;
 
 exportconstcustomInspectSymbol=Symbol.for('nodejs.util.inspect.custom');
+exportconstisBuffer=Symbol.for('titanium.buffer.isBuffer');
 
 constcolorRegExp=/\u001b\[\d\d?m/g;// eslint-disable-line no-control-regex
 
@@ -79,3 +80,36 @@ export function uncurryThis(f) {
 returnf.call.apply(f,arguments);
 };
 }
+
+constALL_PROPERTIES=0;
+constONLY_ENUMERABLE=2;
+
+exportconstpropertyFilter={
+ALL_PROPERTIES,
+ONLY_ENUMERABLE
+};
+
+exportfunctiongetOwnNonIndexProperties(obj,filter){
+constprops=[];
+constkeys=filter===ONLY_ENUMERABLE ? Object.keys(obj) : Object.getOwnPropertyNames(obj);
+for(vari=0;i<keys.length;++i){
+constkey=keys[i];
+if(!isAllDigits(key)){
+props.push(key);
+}
+}
+returnprops;
+}
+
+functionisAllDigits(s){
+if(s.length===0){
+returnfalse;
+}
+for(vari=0;i<s.length;++i){
+constcode=s.charCodeAt(i);
+if(code<48||code>57){
+returnfalse;
+}
+}
+returntrue;
+}

common/Resources/ti.internal/extensions/node/internal/util/inspect.js

@@ -38,12 +38,16 @@ import {
 import{codes,isStackOverflowError}from'../errors';
 import{
 customInspectSymbol,
+getOwnNonIndexProperties,
 isError,
 join,
+propertyFilter,
 removeColors,
 uncurryThis
 }from'../util';
 
+const{ALL_PROPERTIES,ONLY_ENUMERABLE}=propertyFilter;
+
 constBooleanPrototype=Boolean.prototype;
 constDatePrototype=Date.prototype;
 constErrorPrototype=Error.prototype;
@@ -482,34 +486,6 @@ function noPrototypeIterator(ctx, value, recurseTimes) {
 }
 }
 
-functionisAllDigits(s){
-if(s.length===0){
-returnfalse;
-}
-for(vari=0;i<s.length;++i){
-constcode=s.charCodeAt(i);
-if(code<48||code>57){
-returnfalse;
-}
-}
-returntrue;
-}
-
-functiongetOwnNonIndexProperties(obj,filter){
-constprops=[];
-constkeys=filter===ONLY_ENUMERABLE ? Object.keys(obj) : Object.getOwnPropertyNames(obj);
-for(vari=0;i<keys.length;++i){
-constkey=keys[i];
-if(!isAllDigits(key)){
-props.push(key);
-}
-}
-returnprops;
-}
-
-constALL_PROPERTIES=0;
-constONLY_ENUMERABLE=2;
-
 functionformatValue(ctx,value,recurseTimes,typedArray){
 // Primitive types cannot have properties.
 if(typeofvalue!=='object'&&typeofvalue!=='function'){

common/Resources/ti.internal/extensions/node/internal/util/types.js

@@ -1,4 +1,4 @@
-import{uncurryThis}from'../util';
+import{isBuffer,uncurryThis}from'../util';
 
 constTypedArrayPrototype=Object.getPrototypeOf(Uint8Array.prototype);
 
@@ -176,7 +176,12 @@ export function isSymbolObject(value) {
 }
 
 exportfunctionisTypedArray(value){
-returnTypedArrayProto_toStringTag(value)!==undefined;
+constisBuiltInTypedArray=TypedArrayProto_toStringTag(value)!==undefined;
+if(isBuiltInTypedArray){
+returntrue;
+}
+
+returnvalue[isBuffer]===true;
 }
 
 exportfunctionisUint8Array(value){

tests/Resources/util.test.js

@@ -1485,6 +1485,29 @@ describe('util', () => {
 });
 });
 
+describe('#isTypedArray()',()=>{
+it('should return true for built-in typed arrays',()=>{
+should(util.types.isTypedArray(newUint8Array())).be.true;
+should(util.types.isTypedArray(newUint8ClampedArray())).be.true;
+should(util.types.isTypedArray(newUint16Array())).be.true;
+should(util.types.isTypedArray(newUint32Array())).be.true;
+should(util.types.isTypedArray(newInt8Array())).be.true;
+should(util.types.isTypedArray(newInt16Array())).be.true;
+should(util.types.isTypedArray(newInt32Array())).be.true;
+should(util.types.isTypedArray(newFloat32Array())).be.true;
+should(util.types.isTypedArray(newFloat64Array())).be.true;
+});
+
+it('should return true for our own Buffer',()=>{
+should(util.types.isTypedArray(Buffer.alloc())).be.true;
+});
+
+it('should return false for other values',()=>{
+util.types.isTypedArray({}).should.be.false;
+util.types.isTypedArray([]).should.be.false;
+});
+});
+
 describe('Typed Arrays',()=>{
 it('should correctly check typed arrays',()=>{
 should(!util.types.isUint8Array({[Symbol.toStringTag]: 'Uint8Array'})).be.true;