Add --strict option to CLI commands

CHANGELOG.md

@@ -48,6 +48,7 @@ The **third number** is for emergencies when we need to start branches for older
 - New `gpx validate` CLI options:
   - `--strict`: Treat warnings as failures (non-zero exit code).
   - `--json`: Output a machine-readable validation report.
+- New `--strict` option on the `gpx info`, `gpx edit`, `gpx merge` and `gpx convert` CLI commands. When given, each input is validated against the GPX 1.1 schema first: warnings are printed to stderr and the command aborts (non-zero exit code) if any schema errors are found. For `gpx convert`, validation only applies to GPX input. The default keeps the existing lenient behavior.
 
 ### Changed
 

README.md

@@ -466,6 +466,12 @@ gpx merge file1.gpx file2.gpx file3.gpx -o merged.gpx
 gpx convert input.gpx -o output.geojson
 gpx convert input.gpx -o output.kml
 gpx convert input.geojson -o output.gpx
+
+# Validate the input first with --strict (info, edit, merge and convert):
+# prints warnings and aborts on schema errors before doing any work
+gpx info --strict path/to/file.gpx
+gpx edit --strict input.gpx -o output.gpx --simplify 10
+gpx merge --strict file1.gpx file2.gpx -o merged.gpx
 ```
 
 <!-- end docs-include-usage -->

docs/cli.md

@@ -82,7 +82,7 @@ options:
 
 ## gpx info
 
-Display information and statistics about a GPX file.
+Display information and statistics about a GPX file. Use `--strict` to validate the input against the GPX 1.1 schema first, printing warnings and aborting on schema errors.
 
 <!--[[[cog
 help_output(["info", "--help"])
@@ -91,7 +91,7 @@ help_output(["info", "--help"])
 Running `gpx info --help` or `python -m gpx info --help` shows a list of all of the available options and arguments:
 
 ```shell
-usage: gpx info [-h] [--json] <INPUT_FILE>
+usage: gpx info [-h] [--json] [--strict] <INPUT_FILE>
 
 Display detailed information and statistics about a GPX file.
 
@@ -101,13 +101,15 @@ positional arguments:
 options:
   -h, --help    show this help message and exit
   --json        Output information in JSON format
+  --strict      Validate the input against the GPX 1.1 schema first; print
+                warnings and abort on schema errors
 ```
 
 <!--[[[end]]]-->
 
 ## gpx edit
 
-Edit a GPX file with various transformations.
+Edit a GPX file with various transformations. Use `--strict` to validate the input against the GPX 1.1 schema first, printing warnings and aborting on schema errors.
 
 <!--[[[cog
 help_output(["edit", "--help"])
@@ -126,7 +128,7 @@ usage: gpx edit [-h] -o <OUTPUT_FILE> [--min-lat LATITUDE]
                 [--strip-author] [--strip-copyright] [--strip-time]
                 [--strip-keywords] [--strip-links] [--strip-all-metadata]
                 [--strip-extensions] [--precision DIGITS]
-                [--elevation-precision DIGITS]
+                [--elevation-precision DIGITS] [--strict]
                 <INPUT_FILE>
 
 Edit a GPX file with various transformations like cropping, trimming,
@@ -139,6 +141,8 @@ options:
   -h, --help            show this help message and exit
   -o, --output-file <OUTPUT_FILE>
                         Path to the output file
+  --strict              Validate the input against the GPX 1.1 schema first;
+                        print warnings and abort on schema errors
 
 crop options:
   Crop to a geographic bounding box
@@ -218,7 +222,7 @@ precision options:
 
 ## gpx merge
 
-Merge multiple GPX files into a single file.
+Merge multiple GPX files into a single file. Use `--strict` to validate every input against the GPX 1.1 schema first, printing warnings and aborting if any input has schema errors.
 
 <!--[[[cog
 help_output(["merge", "--help"])
@@ -227,7 +231,8 @@ help_output(["merge", "--help"])
 Running `gpx merge --help` or `python -m gpx merge --help` shows a list of all of the available options and arguments:
 
 ```shell
-usage: gpx merge [-h] -o <OUTPUT_FILE> <INPUT_FILE> [<INPUT_FILE> ...]
+usage: gpx merge [-h] -o <OUTPUT_FILE> [--strict]
+                 <INPUT_FILE> [<INPUT_FILE> ...]
 
 Merge multiple GPX files into a single GPX file.
 
@@ -238,13 +243,15 @@ options:
   -h, --help            show this help message and exit
   -o, --output-file <OUTPUT_FILE>
                         Path to the output file
+  --strict              Validate the input against the GPX 1.1 schema first;
+                        print warnings and abort on schema errors
 ```
 
 <!--[[[end]]]-->
 
 ## gpx convert
 
-Convert between GPX, GeoJSON, and KML formats.
+Convert between GPX, GeoJSON, and KML formats. Use `--strict` to validate GPX input against the GPX 1.1 schema first, printing warnings and aborting on schema errors (ignored for non-GPX input).
 
 <!--[[[cog
 help_output(["convert", "--help"])
@@ -254,7 +261,7 @@ Running `gpx convert --help` or `python -m gpx convert --help` shows a list of a
 
 ```shell
 usage: gpx convert [-h] -o <OUTPUT_FILE> [-f {gpx,geojson,kml}]
-                   [-t {gpx,geojson,kml}]
+                   [-t {gpx,geojson,kml}] [--strict]
                    <INPUT_FILE>
 
 Convert GPX files to other file formats or vice versa.
@@ -272,6 +279,8 @@ options:
   -t, --to-format {gpx,geojson,kml}
                         Output format (default: auto-detect from file
                         extension)
+  --strict              Validate the input against the GPX 1.1 schema first;
+                        print warnings and abort on schema errors
 ```
 
 <!--[[[end]]]-->

src/gpx/cli.py

@@ -15,7 +15,7 @@
 from pathlib import Path
 from typing import TYPE_CHECKING
 
-from .io import convert_file, read_gpx
+from .io import convert_file, detect_format, read_gpx
 from .operations import (
     crop,
     reduce_precision,
@@ -29,7 +29,7 @@
     trim,
 )
 from .operations import merge as merge_op
-from .validation import ValidationResult
+from .validation import InvalidGPXError, ValidationResult
 from .validation import validate as validate_gpx
 
 if TYPE_CHECKING:
@@ -215,6 +215,38 @@ def _validate_text_output(
     return 1 if failed else 0
 
 
+def _add_strict_argument(parser: argparse.ArgumentParser) -> None:
+    """Add the shared ``--strict`` option to a file-reading subcommand."""
+    parser.add_argument(
+        "--strict",
+        action="store_true",
+        help="Validate the input against the GPX 1.1 schema first; print "
+        "warnings and abort on schema errors",
+    )
+
+
+def _validate_or_raise(file_path: Path) -> None:
+    """Validate a GPX file, printing warnings and raising on schema errors.
+
+    Any validation warnings are printed to stderr; any schema errors raise
+    :class:`~gpx.validation.InvalidGPXError`, which the CLI reports as an error
+    and exits non-zero. This backs the ``--strict`` option of the file-reading
+    subcommands, mirroring ``read_gpx(..., strict=True)`` while also surfacing
+    warnings.
+    """
+    result = validate_gpx(file_path)
+
+    if result.warnings:
+        n_warnings = len(result.warnings)
+        noun = "warning" if n_warnings == 1 else "warnings"
+        print(f"⚠ {file_path}: {n_warnings} {noun}", file=sys.stderr)
+        for issue in result.warnings:
+            print(f"  {issue}", file=sys.stderr)
+
+    if not result.is_valid:
+        raise InvalidGPXError(result)
+
+
 def _add_info_parser(
     subparsers: argparse._SubParsersAction[argparse.ArgumentParser],
 ) -> None:
@@ -235,6 +267,7 @@ def _add_info_parser(
         action="store_true",
         help="Output information in JSON format",
     )
+    _add_strict_argument(info_parser)
     info_parser.set_defaults(func=info)
 
 
@@ -246,6 +279,9 @@ def info(args: argparse.Namespace) -> int:
         print(f"Error: File not found: {file_path}", file=sys.stderr)
         return 1
 
+    if args.strict:
+        _validate_or_raise(file_path)
+
     gpx = read_gpx(file_path)
 
     info = _gather_gpx_info(gpx)
@@ -696,6 +732,7 @@ def _add_edit_parser(
         help="Number of decimal places for elevation (e.g., 1)",
     )
 
+    _add_strict_argument(edit_parser)
     edit_parser.set_defaults(func=edit)
 
 
@@ -708,6 +745,9 @@ def edit(args: argparse.Namespace) -> int:  # noqa: C901, PLR0912
         print(f"Error: File not found: {input_path}", file=sys.stderr)
         return 1
 
+    if args.strict:
+        _validate_or_raise(input_path)
+
     gpx = read_gpx(input_path)
 
     # Apply crop
@@ -852,6 +892,7 @@ def _add_merge_parser(
         metavar="<OUTPUT_FILE>",
         dest="output_file",
     )
+    _add_strict_argument(parser)
     parser.set_defaults(func=merge)
 
 
@@ -866,6 +907,11 @@ def merge(args: argparse.Namespace) -> int:
             print(f"Error: File not found: {file_path}", file=sys.stderr)
             return 1
 
+    # In strict mode, validate every input before merging any of them.
+    if args.strict:
+        for file_path in files:
+            _validate_or_raise(file_path)
+
     # Read and merge all GPX files
     merged_gpx = merge_op(read_gpx(file_path) for file_path in files)
 
@@ -916,6 +962,7 @@ def _add_convert_parser(
         choices=["gpx", "geojson", "kml"],
         help="Output format (default: auto-detect from file extension)",
     )
+    _add_strict_argument(parser)
     parser.set_defaults(func=convert)
 
 
@@ -928,6 +975,10 @@ def convert(args: argparse.Namespace) -> int:
         print(f"Error: File not found: {input_path}", file=sys.stderr)
         return 1
 
+    # Schema validation only applies to GPX input.
+    if args.strict and (args.from_format or detect_format(input_path)) == "gpx":
+        _validate_or_raise(input_path)
+
     try:
         input_format, output_format = convert_file(
             input_path,