prompt: remove blank lines and code comments before printing

Author: floatingatoll

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 * Convert conditionals to bash-native to simplify maintenance and readability
 * Add internal logic to allow more complex prefix/suffix whitespace logic
+* Remove blank lines and code comments when printing bash/zsh script
 
 ### Added
 * Allow users to disable prompt modification with `MAWS_PROMPT_DISABLE=1`.

mozilla_aws_cli/role_picker.py

@@ -5,13 +5,17 @@
 import platform
 import requests
 import tempfile
+import re
 
 from .cache import read_group_role_map, write_group_role_map
 
 
 logger = logging.getLogger(__name__)
 
-PROMPT_BASH_CODE = r'''
+# we post-process this variable in a specific manner; please take note:
+# 1) blank lines are removed
+# 2) lines that are only a # comment are removed
+prompt_bash_code_original = r'''
 function maws_profile {
     if [[ -n $MAWS_PROMPT ]]; then
         # either a whitespace character or blank, depending on what
@@ -70,6 +74,14 @@
 fi
 '''
 
+# remove blank lines and code comments from the bash script.
+# this permits maintainable code but minimizes what's emitted
+# if the user doesn't use source/eval/<() when calling maws.
+PROMPT_BASH_CODE=""
+for line in prompt_bash_code_original.split("\n"):
+    # skip blank lines and comments
+    if not re.match('^ *(#|$)', line):
+        PROMPT_BASH_CODE += line + "\n"
 
 def output_set_env_vars(var_map, message=None):
     if platform.system() == "Windows":