From daa2f9002316b72770a5554650fd0af77b5e784e Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Fri, 28 Oct 2022 23:39:32 +0800
Subject: [PATCH] scanner: fix and resotre string interpolation tests (#16242)

---
 .../tests/str_interpol_invalid_err.out        | 39 ++++++++++++++-----
 .../checker/tests/str_interpol_invalid_err.vv |  6 +--
 vlib/v/scanner/scanner.v                      |  6 ++-
 .../string_interpolation_inner_cbr_test.v     |  3 --
 4 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/vlib/v/checker/tests/str_interpol_invalid_err.out b/vlib/v/checker/tests/str_interpol_invalid_err.out
index 49b3fb4147..41c68f0423 100644
--- a/vlib/v/checker/tests/str_interpol_invalid_err.out
+++ b/vlib/v/checker/tests/str_interpol_invalid_err.out
@@ -4,31 +4,52 @@ vlib/v/checker/tests/str_interpol_invalid_err.vv:8:13: error: illegal format spe
     8 |     _ = '${[1]:x}'
       |                ^
     9 |     _ = '${[1]!:x}'
-   10 |     //_ = '${Foo{}:x}'
+   10 |     _ = '${Foo{}:x}'
 vlib/v/checker/tests/str_interpol_invalid_err.vv:9:14: error: illegal format specifier `x` for type `[1]int`
     7 | fn main() {
     8 |     _ = '${[1]:x}'
     9 |     _ = '${[1]!:x}'
       |                 ^
-   10 |     //_ = '${Foo{}:x}'
+   10 |     _ = '${Foo{}:x}'
    11 |     _ = '${[1]:f}'
+vlib/v/checker/tests/str_interpol_invalid_err.vv:10:15: error: illegal format specifier `x` for type `Foo`
+    8 |     _ = '${[1]:x}'
+    9 |     _ = '${[1]!:x}'
+   10 |     _ = '${Foo{}:x}'
+      |                  ^
+   11 |     _ = '${[1]:f}'
+   12 |     _ := '${none:F}'
 vlib/v/checker/tests/str_interpol_invalid_err.vv:11:13: error: illegal format specifier `f` for type `[]int`
     9 |     _ = '${[1]!:x}'
-   10 |     //_ = '${Foo{}:x}'
+   10 |     _ = '${Foo{}:x}'
    11 |     _ = '${[1]:f}'
       |                ^
    12 |     _ := '${none:F}'
-   13 |     //_ = '${{"a": "b"}:x}'
+   13 |     _ = '${{"a": "b"}:x}'
 vlib/v/checker/tests/str_interpol_invalid_err.vv:12:15: error: illegal format specifier `F` for type `none`
-   10 |     //_ = '${Foo{}:x}'
+   10 |     _ = '${Foo{}:x}'
    11 |     _ = '${[1]:f}'
    12 |     _ := '${none:F}'
       |                  ^
-   13 |     //_ = '${{"a": "b"}:x}'
-   14 |     //_ = '${Alias(Foo{}):x}'
+   13 |     _ = '${{"a": "b"}:x}'
+   14 |     _ = '${Alias(Foo{}):x}'
+vlib/v/checker/tests/str_interpol_invalid_err.vv:13:20: error: illegal format specifier `x` for type `map[string]string`
+   11 |     _ = '${[1]:f}'
+   12 |     _ := '${none:F}'
+   13 |     _ = '${{"a": "b"}:x}'
+      |                       ^
+   14 |     _ = '${Alias(Foo{}):x}'
+   15 |     _ = '${SumType(int(5)):o}'
+vlib/v/checker/tests/str_interpol_invalid_err.vv:14:22: error: illegal format specifier `x` for type `Alias`
+   12 |     _ := '${none:F}'
+   13 |     _ = '${{"a": "b"}:x}'
+   14 |     _ = '${Alias(Foo{}):x}'
+      |                         ^
+   15 |     _ = '${SumType(int(5)):o}'
+   16 | }
 vlib/v/checker/tests/str_interpol_invalid_err.vv:15:25: error: illegal format specifier `o` for type `SumType`
-   13 |     //_ = '${{"a": "b"}:x}'
-   14 |     //_ = '${Alias(Foo{}):x}'
+   13 |     _ = '${{"a": "b"}:x}'
+   14 |     _ = '${Alias(Foo{}):x}'
    15 |     _ = '${SumType(int(5)):o}'
       |                            ^
    16 | }
diff --git a/vlib/v/checker/tests/str_interpol_invalid_err.vv b/vlib/v/checker/tests/str_interpol_invalid_err.vv
index 79f74e3108..b938fcfc5d 100644
--- a/vlib/v/checker/tests/str_interpol_invalid_err.vv
+++ b/vlib/v/checker/tests/str_interpol_invalid_err.vv
@@ -7,10 +7,10 @@ type SumType = Alias | int
 fn main() {
 	_ = '${[1]:x}'
 	_ = '${[1]!:x}'
-	//_ = '${Foo{}:x}'
+	_ = '${Foo{}:x}'
 	_ = '${[1]:f}'
 	_ := '${none:F}'
-	//_ = '${{"a": "b"}:x}'
-	//_ = '${Alias(Foo{}):x}'
+	_ = '${{"a": "b"}:x}'
+	_ = '${Alias(Foo{}):x}'
 	_ = '${SumType(int(5)):o}'
 }
diff --git a/vlib/v/scanner/scanner.v b/vlib/v/scanner/scanner.v
index 0437d5930b..b65afc3d95 100644
--- a/vlib/v/scanner/scanner.v
+++ b/vlib/v/scanner/scanner.v
@@ -803,11 +803,13 @@ fn (mut s Scanner) text_scan() token.Token {
 			}
 			`{` {
 				if s.is_inside_string {
+					prev_char := s.text[s.pos - 1]
+					next_char := s.text[s.pos + 1]
 					// Handle new `hello {name}` string interpolation
-					if !s.text[s.pos + 1].is_space() && s.text[s.pos - 1] != `$` {
+					if !next_char.is_space() && next_char != `}` && prev_char !in [`$`, `{`] {
 						return s.new_token(.str_dollar, '', 1)
 					}
-					if s.text[s.pos - 1] == `$` {
+					if prev_char == `$` {
 						// Skip { in `${` in strings
 						continue
 					} else {
diff --git a/vlib/v/tests/string_interpolation_inner_cbr_test.v b/vlib/v/tests/string_interpolation_inner_cbr_test.v
index 5dd0df090f..a1c03df9f4 100644
--- a/vlib/v/tests/string_interpolation_inner_cbr_test.v
+++ b/vlib/v/tests/string_interpolation_inner_cbr_test.v
@@ -9,12 +9,9 @@ fn test_string_interpolation_inner_cbr() {
 	println(s1)
 	assert s1 == '22'
 
-	/*
-	XTODO
 	s2 := '${St{}}'
 	println(s2)
 	assert s2 == 'St{}'
-	*/
 
 	s3 := '${{
 		'a': 1