v.pref: error for v file.v --unknown-option (#21391)

Author: JoeyShapiro

vlib/v/pref/pref.v

@@ -924,6 +924,10 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 				if command == 'build' && is_source_file(arg) {
 					eprintln_exit('Use `v ${arg}` instead.')
 				}
+				if is_source_file(arg) && arg.ends_with('.vsh') {
+					// store for future iterations
+					res.is_vsh = true
+				}
 				if !arg.starts_with('-') {
 					if command == '' {
 						command, command_idx = arg, i
@@ -936,10 +940,18 @@ pub fn parse_args_and_show_errors(known_external_commands []string, args []strin
 					}
 					continue
 				}
-				if command !in ['', 'build-module'] {
+				if command !in ['', 'build-module'] && !is_source_file(command) {
 					// arguments for e.g. fmt should be checked elsewhere
 					continue
 				}
+				if res.is_vsh && command_idx < i {
+					// Allow for `script.vsh abc 123 -option`, because -option is for the .vsh program, not for v
+					continue
+				}
+				if command == 'doc' {
+					// Allow for `v doc -comments file.v`
+					continue
+				}
 				err_detail := if command == '' { '' } else { ' for command `${command}`' }
 				eprintln_exit('Unknown argument `${arg}`${err_detail}')
 			}

vlib/v/pref/unknown_options_test.v

@@ -0,0 +1,39 @@
+import os
+
+const tfile = os.join_path(os.vtmp_dir(), 'unknown_options_output.c')
+
+fn test_unknown_option_flags_no_run() {
+	os.chdir(os.dir(@VEXE))!
+	os.rm(tfile) or {}
+
+	res1 := os.execute('${os.quoted_path(@VEXE)} -o ${os.quoted_path(tfile)} examples/hello_world.v --an-unknown-option')
+	assert res1.exit_code == 1
+	assert res1.output.starts_with('Unknown argument')
+	assert res1.output.contains('--an-unknown-option')
+	assert !os.exists(tfile)
+
+	res2 := os.execute('${os.quoted_path(@VEXE)} -o ${os.quoted_path(tfile)} --an-unknown-option examples/hello_world.v')
+	assert res2.exit_code == 1
+	assert res2.output.starts_with('Unknown argument')
+	assert res2.output.contains('--an-unknown-option')
+	assert !os.exists(tfile)
+}
+
+fn test_unknown_option_flags_with_run() {
+	res_run_o := os.execute('${os.quoted_path(@VEXE)} -o ${os.quoted_path(tfile)} run examples/hello_world.v --an-unknown-option')
+	assert res_run_o.exit_code == 0
+	assert res_run_o.output == '' // because of -o, there should not be an actual run, since compilation stopped after generating the .c file
+	assert os.exists(tfile)
+	os.rm(tfile) or {}
+
+	res_run_no_o_unknown_before_run := os.execute('${os.quoted_path(@VEXE)} --an-unknown-option run examples/hello_world.v ')
+	assert res_run_no_o_unknown_before_run.exit_code == 1
+	assert res_run_no_o_unknown_before_run.output.starts_with('Unknown argument')
+	assert res_run_no_o_unknown_before_run.output.contains('--an-unknown-option')
+	assert !os.exists(tfile)
+
+	res_run_no_o := os.execute('${os.quoted_path(@VEXE)} run examples/hello_world.v --an-unknown-option')
+	assert res_run_no_o.exit_code == 0
+	assert res_run_no_o.output.trim_space() == 'Hello, World!'
+	assert !os.exists(tfile)
+}