v2: more informative assert output; string interpolation formatting

vlib/compiler/tests/string_interpolation_test.v

@@ -1,36 +1,57 @@
-
-fn test_simple_string_interpolation(){
+fn test_simple_string_interpolation() {
 	a := 'Hello'
 	b := 'World'
 	res := '$a $b'
 	assert res == 'Hello World'
 }
 
+fn test_mixed_string_interpolation() {
+	num := 7
+	str := 'abc'
+	s1 := 'number=$num'
+	assert s1 == 'number=7'
+	s2 := 'string=$str'
+	assert s2 == 'string=abc'
+	s3 := 'a: $num | b: $str'
+	assert s3 == 'a: 7 | b: abc'
+}
+
+fn test_formatted_string_interpolation() {
+	x := 'abc'
+	axb := 'a:$x:b'
+	assert axb == 'a:abc:b'
+	x_10 := 'a:${x:10s}:b'
+	x10_ := 'a:${x:-10s}:b'
+	assert x_10 == 'a:       abc:b'
+	assert x10_ == 'a:abc       :b'
+	i := 23
+	si_right := '${i:10d}'
+	si__left := '${i:-10d}'
+	assert si_right == '        23'
+	assert si__left == '23        '
+}
+
 fn test_excape_dollar_in_string() {
-  i := 42
-
-  assert '($i)' == '(42)'
-  assert '(\$i)'.contains('i') && !'(\$i)'.contains('42')
-  assert !'(\\$i)'.contains('i') && '(\\$i)'.contains('42') && '(\\$i)'.contains('\\')
-  assert '(\\\$i)'.contains('i') && !'(\\\$i)'.contains('42') && '(\\$i)'.contains('\\')
-  assert !'(\\\\$i)'.contains('i') && '(\\\\$i)'.contains('42') && '(\\\\$i)'.contains('\\\\')
-
-  assert '(${i})' == '(42)'
-  assert '(\${i})'.contains('i') && !'(\${i})'.contains('42')
-  assert !'(\\${i})'.contains('i') && '(\\${i})'.contains('42') && '(\\${i})'.contains('\\')
-  assert '(\\\${i})'.contains('i') && !'(\\\${i})'.contains('42') && '(\\${i})'.contains('\\')
-  assert !'(\\\\${i})'.contains('i') && '(\\\\${i})'.contains('42') && '(\\\\${i})'.contains('\\\\')
-  assert i==42
+	i := 42
+	assert '($i)' == '(42)'
+	assert '(\$i)'.contains('i') && !'(\$i)'.contains('42')
+	assert !'(\\$i)'.contains('i') && '(\\$i)'.contains('42') && '(\\$i)'.contains('\\')
+	assert '(\\\$i)'.contains('i') && !'(\\\$i)'.contains('42') && '(\\$i)'.contains('\\')
+	assert !'(\\\\$i)'.contains('i') && '(\\\\$i)'.contains('42') && '(\\\\$i)'.contains('\\\\')
+	assert '(${i})' == '(42)'
+	assert '(\${i})'.contains('i') && !'(\${i})'.contains('42')
+	assert !'(\\${i})'.contains('i') && '(\\${i})'.contains('42') && '(\\${i})'.contains('\\')
+	assert '(\\\${i})'.contains('i') && !'(\\\${i})'.contains('42') && '(\\${i})'.contains('\\')
+	assert !'(\\\\${i})'.contains('i') && '(\\\\${i})'.contains('42') && '(\\\\${i})'.contains('\\\\')
+	assert i == 42
 }
 
 fn test_implicit_str() {
-  i := 42
-  assert 'int $i' == 'int 42'
-  assert '$i' == '42'
-
-  check := '$i' == '42'
-  assert check
-
-  text := '$i' + '42'
-  assert text == '4242'
+	i := 42
+	assert 'int $i' == 'int 42'
+	assert '$i' == '42'
+	check := '$i' == '42'
+	assert check
+	text := '$i' + '42'
+	assert text == '4242'
 }

vlib/compiler/tests/string_struct_interpolation_test.v

@@ -0,0 +1,25 @@
+
+struct Foo {
+	bar int
+mut:
+	str string
+}
+
+fn (f Foo) baz() string {
+	return 'baz'
+}
+
+fn test_string_method_interpolation() {
+	foo := Foo{}
+	s := 'baz=${foo.baz()}'
+	assert s == 'baz=baz'
+}
+
+fn test_adding_to_mutable_string_field() {
+	mut foo := Foo{10, 'hi'}
+	assert foo.bar == 10
+	assert foo.str == 'hi'
+	foo.str += '!'
+	eprintln( foo.str )
+	assert foo.str == 'hi!'
+}