[JS CS3] Apply Italics with scripting

Question

There's a keyboard shortcut called "Apply Italics", which by default is [cmd]+[shift]+[i] on Mac, and  [ctrl]+[shift]+[i] on Windows. I use it often because it will change text to the correct italic style. For instance text with the style "85 Heavy" will change to "86 Heavy Italic" or "Semibold Display" to "Semibold Display Italic".
Is there any way to access "Apply Italics" with scripting? The action is not available in any menu as far as I know.

Answer 1

I made this script which will change all text with the character style "I" into proper italics, and creates corresponding character styles. "I" is just a character style with no properties. It gets applied when I import content into InDesign.
I will end up with styles called "I 37 Thin Condensed Oblique", "I Italic Display" and so on according to the various fonts.
function applyItalic(){ // Finds all text with Character Style "I" applied in the current document and changes it to proper italic character styles
     var mySelection = app.selection;
     var myDoc = app.activeDocument;
     var myRanges = myDoc.stories.everyItem().textStyleRanges.everyItem().getElements(); // gets every textStyleRange in the document;
     var italicStyle = myDoc.characterStyles.itemByName ("I"); // this character styles has no attributes;
     if (italicStyle == null){
          return;
     var myRange;
     var myFont;
     var newStyle;
     var newStyleName;
     var n;
     for (n=0; n<myRanges.length; n++){
          myRange = myRanges[n];
          if (myRange.appliedCharacterStyle==italicStyle){
               app.select(myRange);
               app.menuActions.itemByID(119611).invoke(); // apply italics - same as [cmd]+[shift]+[i]
               myFont=myRange.appliedFont;
               newStyleName="I "+myFont.fontStyleName;
               newStyle=myDoc.characterStyles.itemByName(newStyleName); // if the style is created
               if (newStyle==null){
                    newStyle=myDoc.characterStyles.add({name: newStyleName, fontStyle: myFont.fontStyleName}); // if the style does not exist yet
               myRange.appliedCharacterStyle=newStyle;
     app.select(mySelection); // restores the original selection
applyItalic();