fix(es/minifier): Preserve cooked while compressing template litera…

…ls (#7773)

**Related issue:**

 - Closes #7770

crates/swc_ecma_minifier/src/compress/pure/strings.rs

@@ -240,7 +240,7 @@ impl Pure<'_> {
         let mut quasis = vec![];
         let mut exprs = vec![];
         let mut cur_raw = String::new();
-        let mut cur_cooked = String::new();
+        let mut cur_cooked = Some(String::new());
 
         for i in 0..(tpl.exprs.len() + tpl.quasis.len()) {
             if i % 2 == 0 {
@@ -249,7 +249,13 @@ impl Pure<'_> {
 
                 cur_raw.push_str(&q.raw);
                 if let Some(cooked) = q.cooked {
-                    cur_cooked.push_str(&cooked);
+                    if let Some(cur_cooked) = &mut cur_cooked {
+                        cur_cooked.push_str(&cooked);
+                    }
+                } else {
+                    // If cooked is None, it means that the template literal contains invalid escape
+                    // sequences.
+                    cur_cooked = None;
                 }
             } else {
                 let i = i / 2;
@@ -258,15 +264,18 @@ impl Pure<'_> {
                 match *e {
                     Expr::Lit(Lit::Str(s)) => {
                         cur_raw.push_str(&convert_str_value_to_tpl_raw(&s.value));
-                        cur_cooked.push_str(&convert_str_value_to_tpl_cooked(&s.value));
+                        if let Some(cur_cooked) = &mut cur_cooked {
+                            cur_cooked.push_str(&convert_str_value_to_tpl_cooked(&s.value));
+                        }
                     }
                     _ => {
                         quasis.push(TplElement {
                             span: DUMMY_SP,
                             tail: true,
-                            cooked: Some(Atom::from(&*cur_cooked)),
+                            cooked: cur_cooked.take().map(From::from),
                             raw: take(&mut cur_raw).into(),
                         });
+                        cur_cooked = Some(String::new());
 
                         exprs.push(e);
                     }
@@ -279,7 +288,7 @@ impl Pure<'_> {
         quasis.push(TplElement {
             span: DUMMY_SP,
             tail: true,
-            cooked: None,
+            cooked: cur_cooked.map(From::from),
             raw: cur_raw.into(),
         });
 

crates/swc_ecma_minifier/tests/fixture/issues/7770/1/input.js

@@ -0,0 +1,13 @@
+exports.MainCSS1 = foo`
+  \x<-invalid, so no cooked
+  ${'this breaks splits the quasis'}
+  this should have a cooked
+`;
+
+exports.MainCSS2 = foo`
+  \x<-invalid, so no cooked
+  ${'this breaks splits the quasis'}
+  this should have a cooked
+  ${'this breaks splits the quasis'}
+  this should also have a cooked
+`;

crates/swc_ecma_minifier/tests/fixture/issues/7770/1/output.js

@@ -0,0 +1,11 @@
+exports.MainCSS1 = foo`
+  \x<-invalid, so no cooked
+  ${'this breaks splits the quasis'}
+  this should have a cooked
+`, exports.MainCSS2 = foo`
+  \x<-invalid, so no cooked
+  ${'this breaks splits the quasis'}
+  this should have a cooked
+  ${'this breaks splits the quasis'}
+  this should also have a cooked
+`;

crates/swc_ecma_minifier/tests/fixture/issues/7770/2/input.js

@@ -0,0 +1,20 @@
+const sWidth = "asdasd";
+function absolute() {
+    return `
+    `;
+}
+function flex() {
+    return `
+    `;
+}
+exports.MainCSS = `
+.ThisshouldOnlyBeonTop {
+    ${absolute()}
+}
+.abcBlablaOne .asdsad {
+    ${flex()}
+}
+.aasdasdasd .asdsada {
+    we: ${sWidth} !important;
+}
+`;

crates/swc_ecma_minifier/tests/fixture/issues/7770/2/output.js

@@ -0,0 +1,13 @@
+exports.MainCSS = `
+.ThisshouldOnlyBeonTop {
+    
+    
+}
+.abcBlablaOne .asdsad {
+    
+    
+}
+.aasdasdasd .asdsada {
+    we: asdasd !important;
+}
+`;