fix bug with escaped quotes in toolrunner _argStringToArray (microsof…

…t#771)

* fix escaped quotes in toolrunner

* add unit test for escaped quotes

* fix output

* fix console

* format code

Co-authored-by: Anna Opareva <v-aopareva@microsoft.com>

node/test/toolrunnertests.ts

@@ -1229,7 +1229,15 @@ describe('Toolrunner Tests', function () {
         assert.equal((node as any).args.toString(), '--path,/bin/working folder1', 'should be --path /bin/working folder1');
         done();
     })
-
+    it('handles escaped quotes', function (done) {
+        this.timeout(10000);
+        var node = tl.tool(tl.which('node', true));
+        node.line('-TEST="escaped\\\"quotes" -x');
+        node.arg('-y');
+        assert.equal((node as any).args.length, 3, 'should have 3 args');
+        assert.equal((node as any).args.toString(), '-TEST=escaped"quotes,-x,-y', 'should be -TEST=escaped"quotes,-x,-y');
+        done();        
+    })
     if (process.platform != 'win32') {
         it('exec prints [command] (OSX/Linux)', function (done) {
             this.timeout(10000);

node/toolrunner.ts

@@ -96,10 +96,13 @@ export class ToolRunner extends events.EventEmitter {
 
         var append = function (c: string) {
             // we only escape double quotes.
-            if (escaped && c !== '"') {
-                arg += '\\';
+            if (escaped) {
+                if (c !== '"') {
+                    arg += '\\';
+                } else {
+                    arg.slice(0, -1);         
+                }
             }
-
             arg += c;
             escaped = false;
         }