Add stdin support

README.md

@@ -28,6 +28,12 @@ cfg.toXML();    // output as a XML string.
 or from a command line:
 ```
 to-json.js input.xml
-to-yaml input.json
-to-xml ipnut.yml
+to-yaml.js input.json
+to-xml.js ipnut.yml
+```
+or via STDIN
+```
+to-json.js < input.xml
+to-yaml.js < input.json
+to-xml.js < ipnut.yml
 ```

bin/to-json.js

@@ -4,6 +4,16 @@ const Path = require('path');
 const Configuration = require(Path.join(__dirname, '..', 'configuration.js'));
 
 let input = process.argv[2];
-let cfg = Configuration.fromFile(input);
+let cfg;
+
+if (input) {
+  // a filename argument was given.
+  cfg = Configuration.fromFile(input);
+
+} else {
+  // no arguments given so read STDIN.
+  cfg = Configuration.fromSTDIN();
+
+}
 
 process.stdout.write(cfg.toJSON());

bin/to-xml.js

@@ -4,6 +4,16 @@ const Path = require('path');
 const Configuration = require(Path.join(__dirname, '..', 'configuration.js'));
 
 let input = process.argv[2];
-let cfg = Configuration.fromFile(input);
+let cfg;
+
+if (input) {
+  // a filename argument was given.
+  cfg = Configuration.fromFile(input);
+
+} else {
+  // no arguments given so read STDIN.
+  cfg = Configuration.fromSTDIN();
+
+}
 
 process.stdout.write(cfg.toXML());

bin/to-yaml.js

@@ -4,6 +4,16 @@ const Path = require('path');
 const Configuration = require(Path.join(__dirname, '..', 'configuration.js'));
 
 let input = process.argv[2];
-let cfg = Configuration.fromFile(input);
+let cfg;
+
+if (input) {
+  // a filename argument was given.
+  cfg = Configuration.fromFile(input);
+
+} else {
+  // no arguments given so read STDIN.
+  cfg = Configuration.fromSTDIN();
+
+}
 
 process.stdout.write(cfg.toYAML());

configuration.js

@@ -8,14 +8,20 @@ const XML = require('fast-xml-parser');
 
 const libPath = Path.join(__dirname, 'lib');
 const Parsers = require(Path.join(libPath, 'parsers.js'));
+const STDIN = require(Path.join(libPath, 'stdin.js'));
 
 
 class Configuration extends Object {
 
-  constructor(input) {
+  constructor(raw, type) {
     super();
 
-    Object.assign(this, input);
+    let parser = Parsers[type];
+    let inpStr = raw.toString();
+
+    let content = parser.parse(inpStr);
+
+    Object.assign(this, content);
   }
 
   toJSON() {
@@ -41,10 +47,27 @@ class Configuration extends Object {
     let type = MIME.lookup(filename);
     let raw = File.readFileSync(filename);
 
-    let parser = Parsers[type];
-    let content = parser.parse(raw.toString());
+    return new this(raw, type);
+  }
+
+  static fromSTDIN() {
+    let raw = this.STDIN.get();
+    let type;
+
+    if (Parsers.isJSON(raw)) {
+      type = MIME.lookup('json');
+    } else if (Parsers.isYAML(raw)) {
+      type = MIME.lookup('yml');
+    } else if (Parsers.isXML(raw)) {
+      type = MIME.lookup('xml');
+    }
+
+    return new this(raw, type);
+  }
 
-    return new this(content);
+  static get STDIN() {
+    // exposed for testability/stubbing.
+    return STDIN;
   }
 
 }

lib/parsers.js

@@ -6,6 +6,25 @@ const Parsers = {
   'text/yaml': YAML,
   'application/json': JSON,
   'application/xml': XML,
+
+  isJSON: function(str) {
+    let match = str.match(/^\{[\{\}\[\]\"\'\w\s\:\,]+[\}\s]$/gi);
+
+    return !!match && match.toString() === str;
+  },
+
+  isYAML: function(str) {
+    let match = str.match(/[\w\s\:\[\]^\{^\}^\<^\>\,\-]+/gi);
+
+    return !!match && match.toString() === str;
+  },
+
+  isXML: function(str) {
+    let match = str.match(/^[\<\>\w\s\/\=\'\"]+$/gi);
+
+    return !!match && match.toString() === str;
+  },
+
 };
 
 

lib/stdin.js

@@ -0,0 +1,37 @@
+
+const File = require('fs');
+
+
+class STDIN {
+
+  static get BUFSIZE() {
+    return this._bufSize || 256;
+  }
+
+  static set BUFSIZE(val) {
+    return this._bufSize = val;
+  }
+
+  static get() {
+    let len = 0;
+    let contents = '';
+    let file = process.stdin.fd;
+
+    let bufSize = this.BUFSIZE;
+    let buf = new Buffer(bufSize);
+
+    do {
+      len = File.readSync(file, buf, 0, bufSize, null);
+
+      let str = buf.toString();
+      contents += str.slice(0, len);
+
+    } while (len > 0);
+
+    return contents;
+  }
+
+}
+
+
+module.exports = STDIN;

spec/configuration_spec.js

@@ -1,8 +1,12 @@
 
 const Path = require('path');
+const File = require('fs');
+
 const YAML = require('yaml');
 const XML = require('fast-xml-parser');
 
+const MIME = require('mime-types');
+
 const specPath = Path.join(__dirname);
 const rootPath = Path.join(specPath, '..');
 const supportPath = Path.join(specPath, 'support');
@@ -24,7 +28,7 @@ describe(Configuration.name, () => {
       instance = Configuration.fromFile(jsonStub);
     });
 
-    describe('the toJSON() function.', () => {
+    describe('the toJSON() function', () => {
       beforeEach(() => {
         result = instance.toJSON();
       });
@@ -41,7 +45,7 @@ describe(Configuration.name, () => {
 
     });
 
-    describe('the toXML() function.', () => {
+    describe('the toXML() function', () => {
       beforeEach(() => {
         result = instance.toXML();
       });
@@ -58,7 +62,7 @@ describe(Configuration.name, () => {
 
     });
 
-    describe('the toYAML() function.', () => {
+    describe('the toYAML() function', () => {
       beforeEach(() => {
         result = instance.toYAML();
       });
@@ -157,4 +161,102 @@ describe(Configuration.name, () => {
 
   });
 
+  describe('the fromSTDIN() static function', () => {
+    let input;
+    let stub;
+    let promise = Promise.resolve();
+    let file;
+
+    beforeEach(() => {
+      let baseLib = Configuration.STDIN;
+
+      input = File.readFileSync(stub);
+
+      spyOn(baseLib, 'get')
+        .and.returnValue(input.toString(), MIME.lookup(stub));
+    });
+
+    describe('given JSON input', () => {
+      stub = jsonStub;
+
+      it('parses the given input object', () => {
+        let res = Configuration.fromSTDIN();
+        let obj = res.anObject;
+
+        expect(obj.one).toEqual(1);
+        expect(obj.two).toEqual(2);
+        expect(obj.three).toEqual(3);
+        expect(obj.four).toEqual(4);
+
+      });
+
+      it('parses the given input array', () => {
+        let res = Configuration.fromSTDIN();
+        let ary = res.anArray;
+
+        expect(ary[0]).toEqual(1);
+        expect(ary[1]).toEqual(2);
+        expect(ary[2]).toEqual(3);
+        expect(ary[3]).toEqual(4);
+
+      });
+
+    });
+
+    describe('given YAML input', () => {
+      stub = yamlStub;
+
+      it('parses the given input object', () => {
+        let res = Configuration.fromSTDIN();
+        let obj = res.anObject;
+
+        expect(obj.one).toEqual(1);
+        expect(obj.two).toEqual(2);
+        expect(obj.three).toEqual(3);
+        expect(obj.four).toEqual(4);
+
+      });
+
+      it('parses the given input array', () => {
+        let res = Configuration.fromSTDIN();
+        let ary = res.anArray;
+
+        expect(ary[0]).toEqual(1);
+        expect(ary[1]).toEqual(2);
+        expect(ary[2]).toEqual(3);
+        expect(ary[3]).toEqual(4);
+
+      });
+
+    });
+
+    describe('given XML input', () => {
+      stub = xmlStub;
+
+      it('parses the given input object', () => {
+        let res = Configuration.fromSTDIN();
+        let obj = res.anObject;
+
+        expect(obj.one).toEqual(1);
+        expect(obj.two).toEqual(2);
+        expect(obj.three).toEqual(3);
+        expect(obj.four).toEqual(4);
+
+      });
+
+      it('parses the given input array', () => {
+        let res = Configuration.fromSTDIN();
+        let ary = res.anArray;
+
+        expect(ary[0]).toEqual(1);
+        expect(ary[1]).toEqual(2);
+        expect(ary[2]).toEqual(3);
+        expect(ary[3]).toEqual(4);
+
+      });
+
+    });
+
+  });
+
 });