twister: Add option to always force color output

Colorama, by default, strips out the color escape characters when the
output is redirected, and this may have an unintended consequence of
disabling color outputs when using a utility such as `tee` and in the
CI runners that redirect the stdout and stderr console outputs.

This commit adds a new command line option called `--force-color` to
always force the ANSI color escape sequence output even when the output
is redirected.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>

scripts/pylib/twister/twisterlib.py

@@ -4716,4 +4716,5 @@ class HardwareMap:
 
         print(tabulate(table, headers=header, tablefmt="github"))
 
-colorama.init()
+def init(colorama_strip):
+    colorama.init(strip=colorama_strip)

scripts/twister

@@ -205,6 +205,7 @@ except ImportError:
 
 sys.path.insert(0, os.path.join(ZEPHYR_BASE, "scripts/pylib/twister"))
 
+import twisterlib
 from twisterlib import HardwareMap, TestPlan, SizeCalculator, CoverageTool, ExecutionCounter
 
 logger = logging.getLogger('twister')
@@ -493,6 +494,10 @@ structure in the main Zephyr tree: boards/<arch>/<board_name>/""")
         is run. This option allows for example to only build tests that can
         actually be run. Runnable is a subset of buildable.""")
 
+    parser.add_argument("--force-color", action="store_true",
+                        help="Always output ANSI color escape sequences "
+                             "even when the output is redirected (not a tty)")
+
     parser.add_argument("--force-toolchain", action="store_true",
                         help="Do not filter based on toolchain, use the set "
                              " toolchain unconditionally")
@@ -833,10 +838,14 @@ def setup_logging(outdir, log_file, verbose, timestamps):
 def main():
     start_time = time.time()
 
-    colorama.init()
-
     options = parse_arguments()
 
+    # Configure color output
+    color_strip = False if options.force_color else None
+
+    colorama.init(strip=color_strip)
+    twisterlib.init(colorama_strip=color_strip)
+
     previous_results = None
     # Cleanup
     if options.no_clean or options.only_failed or options.test_only: