compiler: implement -stats option for running a _test.v file

* Draft implementation of `v -stats file_test.v` .

* compiler: call stuff in vlib/benchmark/tests/always_imported.v, when doing `v -stats file_test.v`

* Nicer looking output from 'v -stats file_test.v' .

* Tweak colors and layout of -stats file_test.v .

* Fix a hardcoded path in compiler/main.v .

* Show colorized OK/FAIL for the examples in 'v test v' too.

* Add some comments about the purpose of the methods inside vlib/benchmark/tests/always_imported.v .

* when fails are 0, do not colorize their number at all.

vlib/benchmark/benchmark.v

@@ -1,6 +1,7 @@
 module benchmark
 
 import time
+import term
 
 /*
 Example usage of this module:
@@ -64,18 +65,40 @@ pub fn (b mut Benchmark) ok() {
 	b.nok++
 }
 
+pub fn (b mut Benchmark) fail_many(n int) {
+	b.step_end_time = benchmark.now()
+	b.ntotal+=n
+	b.nfail+=n
+}
+
+pub fn (b mut Benchmark) ok_many(n int) {
+	b.step_end_time = benchmark.now()
+	b.ntotal+=n
+	b.nok+=n
+}
+
+pub fn (b mut Benchmark) neither_fail_nor_ok() {
+	b.step_end_time = benchmark.now()
+}
+
 pub fn (b mut Benchmark) step_message(msg string) string {
 	return b.tdiff_in_ms(msg, b.step_start_time, b.step_end_time)
 }
 
 pub fn (b mut Benchmark) total_message(msg string) string {
-	mut tmsg := '$msg : ok, fail, total = ${b.nok:5d}, ${b.nfail:5d}, ${b.ntotal:5d}'
+	mut tmsg := '$msg \n ok, fail, total = ' +
+		term.ok_message('${b.nok:5d}') + ', ' +
+		if b.nfail > 0 { term.fail_message('${b.nfail:5d}') } else { '${b.nfail:5d}' } + ', ' +
+		'${b.ntotal:5d}'
 	if b.verbose {
 		tmsg = '<=== total time spent $tmsg'
 	}
 	return b.tdiff_in_ms(tmsg, b.bench_start_time, b.bench_end_time)
 }
 
+pub fn (b mut Benchmark) total_duration() i64 {
+	return (b.bench_end_time - b.bench_start_time)
+}
 ////////////////////////////////////////////////////////////////////
 
 fn (b mut Benchmark) tdiff_in_ms(s string, sticks i64, eticks i64) string {
@@ -89,4 +112,3 @@ fn (b mut Benchmark) tdiff_in_ms(s string, sticks i64, eticks i64) string {
 fn now() i64 {
 	return time.ticks()
 }
-

vlib/benchmark/tests/always_imported.v

@@ -0,0 +1,96 @@
+module main
+
+///////////////////////////////////////////////////////////////////////
+/// This file will get compiled as a part of the same module,
+/// in which a given _test.v file is, when v is given -stats argument
+/// The methods defined here are called back by the test program's
+/// main function, generated by compiler/main.v so that customizing the
+/// look & feel of the results is easy, since it is done in normal V
+/// code, instead of in embedded C ...
+///////////////////////////////////////////////////////////////////////
+
+import os
+import benchmark
+import term
+
+struct BenchedTests {
+mut:
+	oks int
+	fails int
+	test_suit_file string
+	step_func_name string
+	bench benchmark.Benchmark
+}
+
+/////////////////////////////////////////////////////////////////////
+
+// Called at the start of the test program produced by `v -stats file_test.v`
+fn start_testing() BenchedTests {	
+	mut b := BenchedTests{ bench: benchmark.new_benchmark() }
+	b.test_suit_file = os.executable() + '.v'
+	println('running tests in: $b.test_suit_file')
+	return b
+}
+
+// Called before each test_ function, defined in file_test.v
+fn (b mut BenchedTests) testing_step_start(stepfunc string) {
+	b.step_func_name = stepfunc.replace('main__','')
+	b.oks   = C.g_test_oks
+	b.fails = C.g_test_fails
+	b.bench.step()
+}
+
+// Called after each test_ function, defined in file_test.v
+fn (b mut BenchedTests) testing_step_end() {
+	ok_diff   := C.g_test_oks - b.oks
+	fail_diff := C.g_test_fails - b.fails
+	//////////////////////////////////////////////////////////////////
+	if ok_diff == 0 && fail_diff == 0 {
+		b.bench.neither_fail_nor_ok()
+		println('     ' + b.bench.step_message('NO asserts | ') + b.fn_name() )
+		return
+	}	
+	//////////////////////////////////////////////////////////////////
+	if ok_diff   > 0 {
+		b.bench.ok_many(ok_diff)
+	}
+	if fail_diff > 0 {
+		b.bench.fail_many(fail_diff)
+	}
+	//////////////////////////////////////////////////////////////////	
+	if ok_diff   > 0 && fail_diff == 0 {
+		println(ok_text('OK') + b.bench.step_message(nasserts(ok_diff)) + b.fn_name() )
+		return
+	}
+	if fail_diff > 0 {	
+		println(fail_text('FAIL') + b.bench.step_message(nasserts(fail_diff)) + b.fn_name()  )
+		return
+	}
+}
+
+fn (b &BenchedTests) fn_name() string {
+	return b.step_func_name + '()'
+}
+
+// Called at the end of the test program produced by `v -stats file_test.v`
+fn (b mut BenchedTests) end_testing() {
+	b.bench.stop()
+	println( '     ' + b.bench.total_message('running V tests in "' + os.filename(b.test_suit_file) + '"' ) )
+}
+
+/////////////////////////////////////////////////////////////////////
+
+fn nasserts(n int) string {
+	if n==0 { return '${n:2d} asserts | ' }
+	if n==1 { return '${n:2d} assert  | ' }
+	return '${n:2d} asserts | '
+}
+
+fn ok_text(s string) string {
+	return term.ok_message('${s:5s}')
+}
+
+fn fail_text(s string) string {
+	return term.fail_message('${s:5s}')
+}
+

vlib/term/can_show_color.v

@@ -7,3 +7,21 @@ pub fn can_show_color_on_stdout() bool {
 pub fn can_show_color_on_stderr() bool {
 	return can_show_color_on_fd(2)
 }
+
+//////////////////////////////////////////////
+
+pub fn ok_message(s string) string {
+	return if can_show_color_on_stdout() {
+		green( s )
+	}else{
+		s
+	}
+}
+
+pub fn fail_message(s string) string {
+	return if can_show_color_on_stdout() {
+		red( s )
+	}else{
+		s
+	}
+}