Move Comment fetching into click callback

Instead of calling the get_comment() we now have a callback for click,
that's called to validate and transform the given comment id into a
Comment object from JIRA.

jiracli/cli.py

@@ -490,7 +490,12 @@ def comment_create(client, issue):
     client.add_comment(issue.key, text)
 
 
-def get_comment(client, issue, comment_id):
+def get_comment(ctx, param, comment_id):
+    """click callback returning a Comment for the comment_id value given by the user"""
+    from jira.exceptions import JIRAError
+
+    issue = ctx.obj['issue']
+
     if not comment_id:
         from clintermission import cli_select_item
         options = []
@@ -501,18 +506,21 @@ def get_comment(client, issue, comment_id):
             options.append((f"{comment.created} - {comment.author} - {body}", comment.id))
         _, comment_id = cli_select_item(options)
 
-    return client.comment(issue.key, comment_id, expand=['body'])
+    client = ctx.obj['client']
+    try:
+        return client.comment(issue.key, comment_id, expand=['body'])
+    except JIRAError as e:
+        raise click.ClickException(f"Problem retrieving {comment_id} for issue {issue.key}: {e.text}")
 
 
 @comment.command('edit')
-@click.argument('comment_id', required=False)
+@click.argument('comment', required=False, callback=get_comment)
 @pass_issue
 @pass_client
-def comment_edit(client, issue, comment_id):
+def comment_edit(client, issue, comment):
     """Edit the text of an issues comment"""
-    comment = get_comment(client, issue, comment_id)
 
-    text = prompt(f"Comment text to set as new body for comment {comment_id} on {issue.key}",
+    text = prompt(f"Comment text to set as new body for comment {comment.id} on {issue.key}",
                   initial_content=comment.body)
     if text == comment.body:
         print("No changes. Aborting.")
@@ -522,12 +530,10 @@ def comment_edit(client, issue, comment_id):
 
 
 @comment.command('delete')
-@click.argument('comment_id', required=False)
+@click.argument('comment', required=False, callback=get_comment)
 @pass_issue
 @pass_client
-def comment_delete(client, issue, comment_id):
-    comment = get_comment(client, issue, comment_id)
-
+def comment_delete(client, issue, comment):
     # TODO print formatted comment for verification
     click.confirm("Do you really want to delete this ^ ?", abort=True)
     comment.delete()