console: add table method

PR-URL: https://github.com/nodejs/node/pull/18137
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/console.js

@@ -23,11 +23,31 @@
 
 const {
   isStackOverflowError,
-  codes: { ERR_CONSOLE_WRITABLE_STREAM },
+  codes: {
+    ERR_CONSOLE_WRITABLE_STREAM,
+    ERR_INVALID_ARG_TYPE,
+  },
 } = require('internal/errors');
+const { previewMapIterator, previewSetIterator } = require('internal/v8');
+const { Buffer: { isBuffer } } = require('buffer');
+const cliTable = require('internal/cli_table');
 const util = require('util');
+const {
+  isTypedArray, isSet, isMap, isSetIterator, isMapIterator,
+} = util.types;
 const kCounts = Symbol('counts');
 
+const {
+  keys: ObjectKeys,
+  values: ObjectValues,
+} = Object;
+const hasOwnProperty = Function.call.bind(Object.prototype.hasOwnProperty);
+
+const {
+  isArray: ArrayIsArray,
+  from: ArrayFrom,
+} = Array;
+
 // Track amount of indentation required via `console.group()`.
 const kGroupIndent = Symbol('groupIndent');
 
@@ -242,6 +262,113 @@ Console.prototype.groupEnd = function groupEnd() {
     this[kGroupIndent].slice(0, this[kGroupIndent].length - 2);
 };
 
+const keyKey = 'Key';
+const valuesKey = 'Values';
+const indexKey = '(index)';
+const iterKey = '(iteration index)';
+
+
+const isArray = (v) => ArrayIsArray(v) || isTypedArray(v) || isBuffer(v);
+const inspect = (v) => {
+  const opt = { depth: 0, maxArrayLength: 3 };
+  if (v !== null && typeof v === 'object' &&
+      !isArray(v) && ObjectKeys(v).length > 2)
+    opt.depth = -1;
+  return util.inspect(v, opt);
+};
+
+const getIndexArray = (length) => ArrayFrom({ length }, (_, i) => inspect(i));
+
+// https://console.spec.whatwg.org/#table
+Console.prototype.table = function(tabularData, properties) {
+  if (properties !== undefined && !ArrayIsArray(properties))
+    throw new ERR_INVALID_ARG_TYPE('properties', 'Array', properties);
+
+  if (tabularData == null ||
+      (typeof tabularData !== 'object' && typeof tabularData !== 'function'))
+    return this.log(tabularData);
+
+  const final = (k, v) => this.log(cliTable(k, v));
+
+  const mapIter = isMapIterator(tabularData);
+  if (mapIter)
+    tabularData = previewMapIterator(tabularData);
+
+  if (mapIter || isMap(tabularData)) {
+    const keys = [];
+    const values = [];
+    let length = 0;
+    for (const [k, v] of tabularData) {
+      keys.push(inspect(k));
+      values.push(inspect(v));
+      length++;
+    }
+    return final([
+      iterKey, keyKey, valuesKey
+    ], [
+      getIndexArray(length),
+      keys,
+      values,
+    ]);
+  }
+
+  const setIter = isSetIterator(tabularData);
+  if (setIter)
+    tabularData = previewSetIterator(tabularData);
+
+  const setlike = setIter || isSet(tabularData);
+  if (setlike ||
+      (properties === undefined &&
+       (isArray(tabularData) || isTypedArray(tabularData)))) {
+    const values = [];
+    let length = 0;
+    for (const v of tabularData) {
+      values.push(inspect(v));
+      length++;
+    }
+    return final([setlike ? iterKey : indexKey, valuesKey], [
+      getIndexArray(length),
+      values,
+    ]);
+  }
+
+  const map = {};
+  let hasPrimitives = false;
+  const valuesKeyArray = [];
+  const indexKeyArray = ObjectKeys(tabularData);
+
+  for (var i = 0; i < indexKeyArray.length; i++) {
+    const item = tabularData[indexKeyArray[i]];
+    const primitive = item === null ||
+        (typeof item !== 'function' && typeof item !== 'object');
+    if (properties === undefined && primitive) {
+      hasPrimitives = true;
+      valuesKeyArray[i] = inspect(item);
+    } else {
+      const keys = properties || ObjectKeys(item);
+      for (const key of keys) {
+        if (map[key] === undefined)
+          map[key] = [];
+        if ((primitive && properties) || !hasOwnProperty(item, key))
+          map[key][i] = '';
+        else
+          map[key][i] = item == null ? item : inspect(item[key]);
+      }
+    }
+  }
+
+  const keys = ObjectKeys(map);
+  const values = ObjectValues(map);
+  if (hasPrimitives) {
+    keys.push(valuesKey);
+    values.push(valuesKeyArray);
+  }
+  keys.unshift(indexKey);
+  values.unshift(indexKeyArray);
+
+  return final(keys, values);
+};
+
 module.exports = new Console(process.stdout, process.stderr);
 module.exports.Console = Console;