cli: make program outputs using the cli module testable in cli/testdata

vlib/cli/cli_test.v

@@ -1,25 +1,38 @@
 module main
 
-import cli { Command, Flag }
+import v.util.diff
+import term
+import os
 
-fn test_long_description() {
-	mut cmd := Command{
-		name: 'cli'
-		description: 'An example of the cli library.'
-		version: '1.0.0'
-	}
-	mut greet_cmd := Command{
-		name: 'greet'
-		description: 'Prints greeting in different languages.'
-		usage: '<name>'
-		required_args: 1
+const vexe = @VEXE
+const vroot = os.dir(vexe)
+
+fn test_cli_programs() {
+	testdata := os.join_path(vroot, 'vlib', 'cli', 'testdata')
+	mut has_err := false
+	for test in os.walk_ext(testdata, '.vv') {
+		print(test + ' ')
+		out_path := test.all_before_last('.vv') + '.out'
+		if !os.exists(out_path) {
+			println(term.red('FAIL'))
+			eprintln('failed to find output file for `${test}`')
+			has_err = true
+			continue
+		}
+		mut expected_out := os.read_file(out_path)!
+		mut test_out := os.execute('${vexe} run ${test}').output
+		$if windows {
+			expected_out = expected_out.replace('\r\n', '\n')
+			test_out = test_out.replace('\r\n', '\n')
+		}
+		diff_ := diff.compare_text(expected_out, test_out)!
+		if diff_ != '' {
+			println(term.red('FAIL'))
+			eprintln(diff_)
+			has_err = true
+		} else {
+			println(term.green('OK'))
+		}
 	}
-	greet_cmd.add_flag(Flag{
-		flag: .string_array
-		name: 'fun'
-		description: '\'{"uri":"mqtt://broker.emqx.io:1883","topic":"test_emq/1","filters":[{"producer_id":0,"trace_group":2,"string_id":3001},{"string_id":3002}]}\''
-	})
-	cmd.add_command(greet_cmd)
-	cmd.setup()
-	cmd.parse(['cli', 'greet', '-help'])
+	assert !has_err
 }

vlib/v/slow_tests/inout/cli_root_default_control.vv → vlib/cli/testdata/default_command_flag.vv

@@ -1,5 +1,4 @@
 import cli { Command, CommandFlag }
-import os
 
 fn main() {
 	mut cmd := Command{
@@ -10,5 +9,5 @@ fn main() {
 			man: false
 		}
 	}
-	cmd.parse(os.args)
+	cmd.parse([''])
 }

vlib/cli/testdata/long_description.out

@@ -0,0 +1,10 @@
+Usage: cli greet [flags] <name>
+
+Prints greeting in different languages.
+
+Flags:
+  -fun                '{"uri":"mqtt://broker.emqx.io:1883","topic":"test_emq/1
+'{"uri":"mqtt://broker.emqx.io:1883","topic":"test_emq/1","filters":[{"producer_id":0,"trace_group":2,"string_id
+                      ":3001},{"string_id":3002}]}'
+  -help               Prints help information.
+  -man                Prints the auto-generated manpage.

vlib/cli/testdata/long_description.vv

@@ -0,0 +1,21 @@
+import cli { Command, Flag }
+
+mut cmd := Command{
+	name: 'cli'
+	description: 'An example of the cli library.'
+	version: '1.0.0'
+}
+mut greet_cmd := Command{
+	name: 'greet'
+	description: 'Prints greeting in different languages.'
+	usage: '<name>'
+	required_args: 1
+}
+greet_cmd.add_flag(Flag{
+	flag: .string_array
+	name: 'fun'
+	description: '\'{"uri":"mqtt://broker.emqx.io:1883","topic":"test_emq/1","filters":[{"producer_id":0,"trace_group":2,"string_id":3001},{"string_id":3002}]}\''
+})
+cmd.add_command(greet_cmd)
+cmd.setup()
+cmd.parse(['cli', 'greet', '-help'])