Change --text from argument to option

README.md

@@ -143,42 +143,70 @@ Labelle includes the Carlito font, licensed under the
 
 ## Modes
 
-### Print text
+### Overview
 
-```labelle MyText```
+For a comprehensive list of options, run
 
-Multilines will be generated on whitespace
+```bash
+labelle --help
+```
+
+### Preview
 
-```labelle MyLine MySecondLine # Will print two Lines```
+To save tape, you can preview the label without printing it
 
-If you want whitespaces just enclose in " "
+```bash
+labelle --output=console --text Hi
+```
 
-```labelle "prints a single line"```
+![Hi](doc/hi.png)
 
-### Print QRCodes and Barcodes
+### Text
 
-```labelle --help```
+If your text includes whitespace or any other characters like `<` or `$` that are
+interpreted by your shell, then the text must be quoted.
+
+```bash
+labelle --text 'Price: $3.50'
+```
+
+![Price: $3.50](doc/3-50.png)
+
+Multiple text arguments will stack on top of each other as separate lines
+
+```bash
+labelle --text "first line" --text "second line"
+```
+
+![first line second line](doc/two-lines.png)
 
 ### Print Codes and Text
 
 Just add a text after your qr or barcode text
 
-```labelle -qr "QR Content" "Cleartext printed"```
+```bash
+labelle --qr "QR Content" --text "Cleartext printed"
+```
+
+![QR Content Cleartext printed](doc/qr-with-text.png)
 
 ### Picture printing
 
-Any picture with JPEG standard may be printed. Beware it will be downsized to tape.
+Any commonly-supported raster image may be printed.
 
-```labelle -p mypic.jpg ""```
+```bash
+labelle --picture labelle.png
+```
 
-Take care of the trailing "" - you may enter text here which gets printed in
-front of the image
+![labelle.png](doc/labelle-label.png)
 
 ## GUI
 
 ### Run Labelle GUI
 
-```labelle-gui```
+```bash
+labelle-gui
+```
 
 ### GUI App Features
 

pyproject.toml

@@ -92,13 +92,13 @@ commands =
   labelle --version
   labelle --help
   python -c "import labelle.gui.gui; print('GUI import succeeded')"
-  labelle --output console "single line"
-  labelle --output console-inverted "inverted"
-  labelle --output console multiple lines
+  labelle --output console --text "single line"
+  labelle --output console-inverted --text "inverted"
+  labelle --output console --text multiple --text lines
   labelle --output console --barcode "Barcode" --barcode-type code128
-  labelle --output console --barcode-with-text "Barcode" --barcode-type code128 Caption
-  labelle --output console --qr QR
-  labelle --output console --qr QR Caption
+  labelle --output console --barcode-with-text "Barcode" --barcode-type code128 --text "Caption"
+  labelle --output console --qr "QR"
+  labelle --output console --qr "QR" --text "Caption"
   labelle --output console --picture ./labelle.png
 
 [testenv:{clean,build}]

src/labelle/cli/cli.py

@@ -6,12 +6,17 @@
 # this notice are preserved.
 # === END LICENSE STATEMENT ===
 import logging
+import shlex
+import sys
 from pathlib import Path
 from typing import List, NoReturn, Optional
 
 import typer
+from click.exceptions import ClickException
+from click.exceptions import UsageError as ClickUsageError
 from rich.console import Console
 from rich.table import Table
+from typer.rich_utils import rich_format_error
 from typing_extensions import Annotated
 
 from labelle import __version__
@@ -130,7 +135,7 @@ def default(
     ] = None,
     text: Annotated[
         Optional[List[str]],
-        typer.Argument(
+        typer.Option(
             help="Text, each parameter gives a new line",
             rich_help_panel="Elements",
         ),
@@ -554,9 +559,33 @@ def default(
         output_bitmap(bitmap, output)
 
 
+def add_hint_about_text_option(e: ClickException) -> None:
+    """Insert a suggestion to use the --text flag when a command is not found.
+
+    In dymoprint the --text option was implicit. If labelle is invoked without
+    --text, it presents as a ClickUsageError with the message "No such command..."
+    We append to this error message a hint to use the --text flag.
+    """
+    if isinstance(e, ClickUsageError):
+        # Enhance the error message for dymoprint users who are
+        # not used to the --text flag being mandatory.
+        if e.message.startswith("No such command '") and e.message.endswith("'."):
+            command = e.message[17:-2]
+            e.message += f""" Did you mean {shlex.join(['--text', command])} ?"""
+
+
 def main() -> None:
     configure_logging()
-    app()
+    try:
+        app(standalone_mode=False)
+    except ClickException as e:
+        # Use standalone mode to avoid typer's default error handling here:
+        # <https://github.com/tiangolo/typer/blob/773927208fbf03d30d50fc39fe2a1a18b7bd93cb/typer/core.py#L207-L216>
+        # This allows us to add the following hint:
+        add_hint_about_text_option(e)
+
+        rich_format_error(e)
+        sys.exit(e.exit_code)
 
 
 if __name__ == "__main__":

src/labelle/cli/tests/test_cli.py

@@ -0,0 +1,25 @@
+import sys
+
+import pytest
+from typer.testing import CliRunner
+
+from labelle.cli.cli import main
+
+runner = CliRunner()
+
+
+def test_text_hint(monkeypatch):
+    # This is NOT the recommended way of testing Typer applications.
+    # We are doing it this way because we added additional error handling
+    # in main() which we need to test.
+    with monkeypatch.context() as m:
+        m.setattr(sys, "argv", ["labelle", "hello world"])
+        with runner.isolation(input=None, env=None, color=False) as outstreams:
+            with pytest.raises(SystemExit):
+                main()
+            sys.stdout.flush()
+            stdout = outstreams[0].getvalue()
+    assert (
+        b"""No such command 'hello world'. Did you mean --text 'hello world' ?"""
+        in stdout
+    )