fix(uiGridColumns): Fix auto-incrementing of column names

When generating unique column names, do not consider the displayName.
Increment column name property only, using the field as the base.
Increment displayName property only if it is auto-generated,
displaying any provided displayName unchanged.

Fixes: #3453

src/js/core/factories/Grid.js

@@ -983,51 +983,14 @@ angular.module('ui.grid')
     //field was required in 2.x.  now name is required
     if (colDef.name === undefined && colDef.field !== undefined) {
       // See if the column name already exists:
-      var foundName = self.getColumn(colDef.field);
-
-      // If a column with this name already  exists, we will add an incrementing number to the end of the new column name
-      if (foundName) {
-        // Search through the columns for names in the format: <name><1, 2 ... N>, i.e. 'Age1, Age2, Age3',
-        var nameRE = new RegExp('^' + colDef.field + '(\\d+)$', 'i');
-
-        var foundColumns = self.columns.filter(function (column) {
-          // Test against the displayName, as that's what'll have the incremented number
-          return nameRE.test(column.displayName);
-        })
-        // Sort the found columns by the end-number
-        .sort(function (a, b) {
-          if (a === b) {
-            return 0;
-          }
-          else {
-            var numA = a.displayName.match(nameRE)[1];
-            var numB = b.displayName.match(nameRE)[1];
-
-            return parseInt(numA, 10) > parseInt(numB, 10) ? 1 : -1;
-          }
-        });
-
-        // Not columns found, so start with number "2"
-        if (foundColumns.length === 0) {
-          colDef.name = colDef.field + '2';
-        }
-        else {
-          // Get the number from the final column
-          var lastNum = foundColumns[foundColumns.length-1].displayName.match(nameRE)[1];
-
-          // Make sure to parse to an int
-          lastNum = parseInt(lastNum, 10);
-
-          // Add 1 to the number from the last column and tack it on to the field to be the name for this new column
-          colDef.name = colDef.field + (lastNum + 1);
-        }
-      }
-      // ... otherwise just use the field as the column name
-      else {
-        colDef.name = colDef.field;
+      var newName = colDef.field,
+        counter = 2;
+      while (self.getColumn(newName)) {
+        newName = colDef.field + counter.toString();
+        counter++;
       }
+      colDef.name = newName;
     }
-
   };
 
   // Return a list of items that exist in the `n` array but not the `o` array. Uses optional property accessors passed as third & fourth parameters

test/unit/core/factories/GridColumn.spec.js

@@ -114,28 +114,47 @@ describe('GridColumn factory', function () {
 
         buildCols();
 
+        expect(grid.columns[0].name).toEqual('age');
+        expect(grid.columns[1].name).toEqual('name');
+        expect(grid.columns[2].name).toEqual('name2');
+        expect(grid.columns[3].name).toEqual('name3');
+      });
+
+      it('should not change the displayNames if they are provided', function () {
+        var cols = [
+          { field: 'age' },
+          { field: 'name', displayName:'First Name' },
+          { field: 'name', displayName:'First Name' },
+          { field: 'name', displayName:'First Name' }
+        ];
+
+        grid.options.columnDefs = cols;
+
+        buildCols();
+
         expect(grid.columns[0].displayName).toEqual('Age');
-        expect(grid.columns[1].displayName).toEqual('Name');
-        expect(grid.columns[2].displayName).toEqual('Name2');
-        expect(grid.columns[3].displayName).toEqual('Name3');
+        expect(grid.columns[1].displayName).toEqual('First Name');
+        expect(grid.columns[2].displayName).toEqual('First Name');
+        expect(grid.columns[3].displayName).toEqual('First Name');
+
       });
 
       it('should account for existing incremented names', function () {
         var cols = [
           { field: 'age' },
           { field: 'name' },
-          { field: 'name', name: 'Name3' },
+          { field: 'name', name: 'name3' },
           { field: 'name' }
         ];
 
         grid.options.columnDefs = cols;
 
         buildCols();
 
-        expect(grid.columns[0].displayName).toEqual('Age');
-        expect(grid.columns[1].displayName).toEqual('Name');
-        expect(grid.columns[2].displayName).toEqual('Name3');
-        expect(grid.columns[3].displayName).toEqual('Name4');
+        expect(grid.columns[0].name).toEqual('age');
+        expect(grid.columns[1].name).toEqual('name');
+        expect(grid.columns[2].name).toEqual('name3');
+        expect(grid.columns[3].name).toEqual('name2');
       });
     });
   });