refactor clearing and executing first cell in test

IPython/html/tests/casperjs/test_cases/nb_roundtrip.js

@@ -1,111 +1,112
 // Test opening a rich notebook, saving it, and reopening it again.
 //
 //toJSON fromJSON toJSON and do a string comparison
 
 
 // this is just a copy of OutputArea.mime_mape_r in IPython/html/static/notebook/js/outputarea.js
 mime =  {
         "text" : "text/plain",
         "html" : "text/html",
         "svg" : "image/svg+xml",
         "png" : "image/png",
         "jpeg" : "image/jpeg",
         "latex" : "text/latex",
         "json" : "application/json",
         "javascript" : "application/javascript",
     };
     
 // helper function to ensure that the short_name is found in the toJSON
 // represetnation, while the original in-memory cell retains its long mimetype
 // name, and that fromJSON also gets its long mimetype name
 function assert_has(short_name, json, result, result2) {
     long_name = mime[short_name];
     this.test.assertTrue(json[0].hasOwnProperty(short_name),
             'toJSON()   representation uses ' + short_name);
     this.test.assertTrue(result.hasOwnProperty(long_name),
             'toJSON()   original embeded JSON keeps ' + long_name);
     this.test.assertTrue(result2.hasOwnProperty(long_name),
             'fromJSON() embeded ' + short_name + ' gets mime key ' + long_name);
 }
           
 // helper function for checkout that the first two cells have a particular
 // output_type (either 'pyout' or 'display_data'), and checks the to/fromJSON
 // for a set of mimetype keys, using their short names ('javascript', 'text',
 // 'png', etc).
 function check_output_area(output_type, keys) {
     json = this.evaluate(function() {
         var json = IPython.notebook.get_cell(0).output_area.toJSON();
         // appended cell will initially be empty, lets add it some output
         var cell = IPython.notebook.get_cell(1).output_area.fromJSON(json);
         return json;
     });
     var result = this.get_output_cell(0);
     var result2 = this.get_output_cell(1);
     this.test.assertEquals(result.output_type, output_type,
         'testing ' + output_type + ' for ' + keys.join(' and '));
 
     for (var idx in keys) {
         assert_has.apply(this, [keys[idx], json, result, result2]);
     }
 }
 
+
+// helper function to clear the first two cells, set the text of and execute
+// the first one
+function clear_and_execute(that, code) {
+    that.evaluate(function() {
+        IPython.notebook.get_cell(0).clear_output();
+        IPython.notebook.get_cell(1).clear_output();
+    });
+    that.set_cell_text(0, code);
+    that.execute_cell(0);
+}
+
 casper.notebook_test(function () {
     this.evaluate(function () {
         var cell = IPython.notebook.get_cell(0);
         // "we have to make messes to find out who we are"
         cell.set_text([
             "%%javascript",
             "IPython.notebook.insert_cell_below('code')"
             ].join('\n')
             );
 
         cell.execute();
     });
 
     this.wait_for_output(0);
 
     this.then(function ( ) {
         var result = this.get_output_cell(0);
         var num_cells = this.get_cells_length();
         this.test.assertEquals(num_cells, 2, '%%javascript magic works');
         this.test.assertTrue(result.hasOwnProperty('application/javascript'),
             'testing JS embeded with mime key');
     });
 
     //this.thenEvaluate(function() { IPython.notebook.save_notebook(); });
 
     this.then(function ( ) {
         check_output_area.apply(this, ['display_data', ['javascript']]);
 
     });
 
     this.then(function() {
-        // test output of text/plain and application/json keys
-        this.evaluate(function() {
-            IPython.notebook.get_cell(0).clear_output();
-            IPython.notebook.get_cell(1).clear_output();
-        });
-        this.set_cell_text(0, "%lsmagic");
-        this.execute_cell(0);
+        clear_and_execute(this, '%lsmagic');
     });
    
     this.then(function () {
         check_output_area.apply(this, ['pyout', ['text', 'json']]);
     });
 
     this.then(function() {
-        // test display of text/plain and application/json keys
-        this.evaluate(function() {
-            IPython.notebook.get_cell(0).clear_output();
-            IPython.notebook.get_cell(1).clear_output();
-        });
-        this.set_cell_text(0,
+        clear_and_execute(this,
             "x = %lsmagic\nfrom IPython.display import display; display(x)");
         this.execute_cell(0);
     });
 
     this.then(function ( ) {
         check_output_area.apply(this, ['display_data', ['text', 'json']]);
     });
 
 });