test(argparse): group tests by behavior

argparse/command_test.mbt

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+// Copyright 2026 International Digital Economy Academy
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+///|
+fn empty_env() -> Map[String, String] {
+  Map([])
+}
+
+///|
+test "declarative parse basics" {
+  let cmd = @argparse.Command(
+    "demo",
+    flags=[FlagArg("verbose", short='v', long="verbose")],
+    options=[OptionArg("count", long="count", env="COUNT")],
+    positionals=[PositionArg("name")],
+  )
+  let matches = cmd.parse(argv=["-v", "--count", "3", "alice"], env=empty_env()) catch {
+    _ => panic()
+  }
+  assert_true(matches.flags is { "verbose": true, .. })
+  assert_true(matches.values is { "count": ["3"], "name": ["alice"], .. })
+  assert_true(
+    matches.sources is { "verbose": Argv, "count": Argv, "name": Argv, .. },
+  )
+}
+
+///|
+test "command policies" {
+  let help_cmd = @argparse.Command("demo", arg_required_else_help=true)
+  inspect(
+    help_cmd.render_help(),
+    content=(
+      #|Usage: demo
+      #|
+      #|Options:
+      #|  -h, --help  Show help information.
+      #|
+    ),
+  )
+
+  let sub_cmd = @argparse.Command("demo", subcommand_required=true, subcommands=[
+    Command("echo"),
+  ])
+  inspect(
+    sub_cmd.render_help(),
+    content=(
+      #|Usage: demo <command>
+      #|
+      #|Commands:
+      #|  echo  
+      #|  help  Print help for the subcommand(s).
+      #|
+      #|Options:
+      #|  -h, --help  Show help information.
+      #|
+    ),
+  )
+  try sub_cmd.parse(argv=[], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: the following required argument was not provided: 'subcommand'
+          #|
+          #|Usage: demo <command>
+          #|
+          #|Commands:
+          #|  echo  
+          #|  help  Print help for the subcommand(s).
+          #|
+          #|Options:
+          #|  -h, --help  Show help information.
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+}

argparse/errors_test.mbt

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+// Copyright 2026 International Digital Economy Academy
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+///|
+test "unknown argument keeps suggestion in final message" {
+  let cmd = @argparse.Command("demo", flags=[FlagArg("verbose", long="verbose")])
+
+  try cmd.parse(argv=["--verbse"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '--verbse' found
+          #|
+          #|  tip: a similar argument exists: '--verbose'
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  -h, --help  Show help information.
+          #|  --verbose   
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+}
+
+///|
+test "parse error show is readable" {
+  let cmd = @argparse.Command(
+    "demo",
+    flags=[FlagArg("verbose", long="verbose")],
+    positionals=[PositionArg("name")],
+  )
+
+  try cmd.parse(argv=["--verbse"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '--verbse' found
+          #|
+          #|  tip: a similar argument exists: '--verbose'
+          #|
+          #|Usage: demo [options] [name]
+          #|
+          #|Arguments:
+          #|  name  
+          #|
+          #|Options:
+          #|  -h, --help  Show help information.
+          #|  --verbose   
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+
+  try cmd.parse(argv=["alice", "bob"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected value 'bob' for '<name>' found; no more were expected
+          #|
+          #|Usage: demo [options] [name]
+          #|
+          #|Arguments:
+          #|  name  
+          #|
+          #|Options:
+          #|  -h, --help  Show help information.
+          #|  --verbose   
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+}
+
+///|
+test "unknown argument suggestions are exposed" {
+  let cmd = @argparse.Command("demo", flags=[
+    FlagArg("verbose", short='v', long="verbose"),
+  ])
+
+  try cmd.parse(argv=["--verbse"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '--verbse' found
+          #|
+          #|  tip: a similar argument exists: '--verbose'
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  -h, --help     Show help information.
+          #|  -v, --verbose  
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+
+  try cmd.parse(argv=["-x"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '-x' found
+          #|
+          #|  tip: a similar argument exists: '-v'
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  -h, --help     Show help information.
+          #|  -v, --verbose  
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+
+  try cmd.parse(argv=["--zzzzzzzzzz"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '--zzzzzzzzzz' found
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  -h, --help     Show help information.
+          #|  -v, --verbose  
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+}
+
+///|
+test "unified error message formatting remains stable" {
+  let cmd = @argparse.Command("demo", options=[OptionArg("tag", long="tag")])
+
+  try cmd.parse(argv=["--oops"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '--oops' found
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  -h, --help   Show help information.
+          #|  --tag <tag>  
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+
+  try cmd.parse(argv=["--tag"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: a value is required for '--tag' but none was supplied
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  -h, --help   Show help information.
+          #|  --tag <tag>  
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+}
+
+///|
+test "unknown short suggestion can be absent" {
+  let cmd = @argparse.Command("demo", disable_help_flag=true, options=[
+    OptionArg("name", long="name"),
+  ])
+
+  try cmd.parse(argv=["-x"], env=empty_env()) catch {
+    err =>
+      inspect(
+        err,
+        content=(
+          #|error: unexpected argument '-x' found
+          #|
+          #|Usage: demo [options]
+          #|
+          #|Options:
+          #|  --name <name>  
+          #|
+        ),
+      )
+  } noraise {
+    _ => panic()
+  }
+}
+
+///|
+test "Debug for argparse enums" {
+  @debug.debug_inspect(@argparse.FlagAction::SetTrue, content="SetTrue")
+  @debug.debug_inspect(@argparse.FlagAction::Count, content="Count")
+  @debug.debug_inspect(@argparse.OptionAction::Set, content="Set")
+  @debug.debug_inspect(@argparse.OptionAction::Append, content="Append")
+}