stream-json - npm Package Compare versions

Comparing version 0.6.0 to 0.6.1

package.json

 {
   "name": "stream-json",
-  "version": "0.6.0",
+  "version": "0.6.1",
   "description": "stream-json is a SAX-inspired stream components with a minimal memory footprint to parse huge JSON files. Includes utilities to stream Django-like JSON database dumps.",
@@ -5,0 +5,0 @@ "homepage": "http://github.com/uhop/stream-json",

README.md

@@ -25,2 +25,3 @@ # stream-json
   * `Assembler` to assemble full objects from an event stream.
+  * `Stringer` to convert an event stream back to a JSON text stream.
   * `StreamArray` handles a frequent use case: a huge array of relatively small objects similar to [Django](https://www.djangoproject.com/)-produced database dumps. It streams array components individually taking care of assembling them automatically.
@@ -403,2 +404,24 @@ * `StreamFilteredArray` is a companion for `StreamArray`. The difference is that it allows to filter out unneeded objects in an efficient way without assembling them fully.
 
+### utils/Stringer
+
+This stream component converts an event stream (described in this document) back to a JSON text stream. The common use is to filter/transform an input stream, then pipe it back to the original text form.
+
+Its `Writeable` part operates in an [objectMode](http://nodejs.org/api/stream.html#stream_object_mode), while its `Readable` part operates in a buffer mode.
+
+```js
+var makeSource = require("stream-json");
+var Filter     = require("stream-json/Filter");
+var Stringer   = require("stream-json/utils/Stringer");
+
+var source    = makeSource(sourceOptions),
+    filter    = new Filter(filterOptions),
+    stringer  = new Stringer();
+
+// Example of use:
+source.output.pipe(filter).pipe(stringer).pipe(fs.createWriteStream(oname));
+fs.createReadStream(fname).pipe(source.input);
+```
+
+The test file for `Stringer`: `tests/test_stringer.js`.
+
 ### utils/StreamArray
@@ -696,8 +719,10 @@
 
-- 0.5.3 *bug fix to allow empty JSON Streaming*
-- 0.5.2 *bug fixes in `Filter`*
-- 0.5.1 *corrected README*
-- 0.5.0 *added support for [JSON Streaming](https://en.wikipedia.org/wiki/JSON_Streaming)*
+- 0.6.1 *the technical release.*
+- 0.6.0 *added Stringer to convert event streams back to JSON.*
+- 0.5.3 *bug fix to allow empty JSON Streaming.*
+- 0.5.2 *bug fixes in `Filter`.*
+- 0.5.1 *corrected README.*
+- 0.5.0 *added support for [JSON Streaming](https://en.wikipedia.org/wiki/JSON_Streaming).*
 - 0.4.2 *refreshed dependencies.*
-- 0.4.1 *added `StreamObject` by [Sam Noedel](https://github.com/delta62)*
+- 0.4.1 *added `StreamObject` by [Sam Noedel](https://github.com/delta62).*
 - 0.4.0 *new high-performant Combo component, switched to the previous parser.*
@@ -704,0 +729,0 @@ - 0.3.0 *new even faster parser, bug fixes.*

tests/test_stringer.js

@@ -15,5 +15,5 @@ "use strict";
 
-		var source = makeSource(),
-			assembler = new Assembler(),
-			pattern = {
+		var source   = makeSource(),
+			stringer = new Stringer(),
+			pattern  = {
 				a: [[[]]],
@@ -34,12 +34,48 @@ b: {a: 1},
 
-		stream.output.on("data", function(data) {
+		source.output.pipe(stringer);
+
+		stringer.on("data", function(data) {
 			buffer += data;
 		});
-		stream.output.on("end", function(){
-			eval(t.TEST("string === buffer"));
+		stringer.on("end", function() {
+			eval(t.TEST('string === buffer'));
 			async.done();
 		});
 
-		new ReadString(string).pipe(stream.input);
+		new ReadString(string).pipe(source.input);
+	},
+	function test_stringer_json_stream (t) {
+		var async = t.startAsync("test_stringer_json_stream");
+
+		var source   = makeSource({jsonStreaming: true}),
+			stringer = new Stringer(),
+			pattern  = {
+				a: [[[]]],
+				b: {a: 1},
+				c: {a: 1, b: 2},
+				d: [true, 1, "'x\"y'", null, false, true, {}, [], ""],
+				e: 1,
+				f: "",
+				g: true,
+				h: false,
+				i: null,
+				j: [],
+				k: {}
+			},
+			string = JSON.stringify(pattern),
+			buffer = '';
+		string += string;
+
+		source.output.pipe(stringer);
+
+		stringer.on("data", function(data) {
+			buffer += data;
+		});
+		stringer.on("end", function() {
+			eval(t.TEST('string === buffer'));
+			async.done();
+		});
+
+		new ReadString(string).pipe(source.input);
 	}
 ]);

utils/Stringer.js

@@ -13,6 +13,10 @@ 'use strict';
 	this._prev = '';
+	this._depth = 0;
 }
 util.inherits(Stringer, Transform);
 
-var noCommaAfter = {startObject: 1, startArray: 1, endKey: 1},
+var noCommaAfter   = {startObject: 1, startArray: 1, endKey: 1},
+	depthIncrement = {startObject: 1, startArray: 1},
+	depthDecrement = {endObject: 1, endArray: 1},
+	values  = {keyValue: 1, stringValue: 1, numberValue: 1},
 	symbols = {
@@ -27,30 +31,28 @@ startObject: '{', endObject: '}',
 Stringer.prototype._transform = function transform (chunk, encoding, callback) {
-	switch (chunk.name) {
-		case 'endObject':
-		case 'endArray':
-		case 'endKey':
-		case 'endString':
-		case 'endNumber':
-			this.push(symbols[chunk.name]);
-			break;
-		case 'stringChunk':
-			this.push(chunk.value.replace(/\"/g, '\\"'));
-			break;
-		case 'numberChunk':
-			this.push(chunk.value);
-			break;
-		default:
-		// case 'startObject':
-		// case 'startArray':
-		// case 'startKey':
-		// case 'startString':
-		// case 'startNumber':
-		// case 'nullValue':
-		// case 'truelValue':
-		// case 'falseValue':
-			if (noCommaAfter[this._prev] !== 1) this.push(',');
-			this.push(symbols[chunk.name]);
-			break;
+	if (values[chunk.name] !== 1) { // filter out values
+		switch (chunk.name) {
+			case 'endObject': case 'endArray': case 'endKey': case 'endString':
+			case 'endNumber':
+				this.push(symbols[chunk.name]);
+				break;
+			case 'stringChunk':
+				this.push(chunk.value.replace(/\"/g, '\\"'));
+				break;
+			case 'numberChunk':
+				this.push(chunk.value);
+				break;
+			default:
+			// case 'startObject': case 'startArray': case 'startKey': case 'startString':
+			// case 'startNumber': case 'nullValue': case 'truelValue': case 'falseValue':
+				if (this._depth && noCommaAfter[this._prev] !== 1) this.push(',');
+				this.push(symbols[chunk.name]);
+				break;
+		}
+		if (depthIncrement[chunk.name]) {
+			++this._depth;
+		} else if (depthDecrement[chunk.name]) {
+			--this._depth;
+		}
+		this._prev = chunk.name;
 	}
-	this._prev = chunk.name;
 	callback();
@@ -57,0 +59,0 @@ };

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Improved metrics

Total package byte prevSize

222910

increased by0.96%

Lines of code

3981

increased by0.84%

Number of lines in readme file

745

increased by3.47%

Worsened metrics

Number of medium supply chain risk alerts

250

increased by0.4%

No dependency changes