Do not use a generated ident for literals

src/tests/string_method_test.rs

@@ -115,8 +115,8 @@ mod tests {
         let js_file = "test.js".to_string();
         let rewritten = rewrite_js(original_code, js_file).map_err(|e| e.to_string())?;
         assert_that(&rewritten.code)
-            .contains("let __datadog_test_0, __datadog_test_1, __datadog_test_2;
-    const a = (__datadog_test_0 = 1, __datadog_test_1 = String.prototype.concat, __datadog_test_2 = a(), _ddiast.stringConcat(__datadog_test_1.call(__datadog_test_0, __datadog_test_2, 3), __datadog_test_1, __datadog_test_0, __datadog_test_2, 3));");
+            .contains("let __datadog_test_0, __datadog_test_1;
+    const a = (__datadog_test_0 = String.prototype.concat, __datadog_test_1 = a(), _ddiast.stringConcat(__datadog_test_0.call(1, __datadog_test_1, 3), __datadog_test_0, 1, __datadog_test_1, 3));");
         Ok(())
     }
 

src/transform/call_expr_transform.rs

@@ -255,9 +255,11 @@ fn replace_call_expr_if_csi_method_with_member(
         let mut call_replacement = call.clone();
 
         // __datadog_token_$i = a
-        let ident_replacement =
+        let ident_replacement_option =
             ident_provider.get_temporal_ident_used_in_assignation(expr, &mut assignations, &span);
 
+        let ident_replacement = ident_replacement_option.map_or_else(|| expr.clone(), Expr::Ident);
+
         let ident_callee = match member_expr_opt {
             Some(member_expr) => {
                 // __datadog_token_$i2 = member
@@ -272,7 +274,7 @@ fn replace_call_expr_if_csi_method_with_member(
                 // __datadog_token_$i.substring
                 let member_expr = MemberExpr {
                     span,
-                    obj: Box::new(Expr::Ident(ident_replacement.clone())),
+                    obj: Box::new(ident_replacement.clone()),
                     prop: MemberProp::Ident(ident_name.clone()),
                 };
 
@@ -286,12 +288,12 @@ fn replace_call_expr_if_csi_method_with_member(
             }
         };
 
-        arguments.push(Expr::Ident(ident_replacement.clone()));
+        arguments.push(ident_replacement.clone());
 
         // change callee to __datadog_token_$i2.call
         call_replacement.callee = Callee::Expr(Box::new(Expr::Member(MemberExpr {
             span,
-            obj: Box::new(Expr::Ident(ident_callee)),
+            obj: Box::new(ident_callee.map_or_else(|| expr.clone(), Expr::Ident)),
             prop: MemberProp::Ident(IdentName::new(JsWord::from("call"), span)),
         })));
 
@@ -311,7 +313,7 @@ fn replace_call_expr_if_csi_method_with_member(
             0,
             ExprOrSpread {
                 spread: None,
-                expr: Box::new(Expr::Ident(ident_replacement)),
+                expr: Box::new(ident_replacement),
             },
         );
 

src/transform/operand_handler.rs

@@ -27,12 +27,14 @@ pub trait OperandHandler {
             Expr::Ident(_) => {
                 if ident_mode == IdentMode::Replace {
                     operand.map_with_mut(|op| {
-                        Expr::Ident(ident_provider.get_ident_used_in_assignation(
+                        let ident = ident_provider.get_ident_used_in_assignation(
                             &op,
                             assignations,
                             arguments,
                             span,
-                        ))
+                        );
+
+                        ident.map_or(op, Expr::Ident)
                     })
                 } else {
                     arguments.push(operand.clone())
@@ -70,12 +72,10 @@ pub trait OperandHandler {
         ident_provider: &mut dyn IdentProvider,
     ) {
         operand.map_with_mut(|op| {
-            Expr::Ident(ident_provider.get_ident_used_in_assignation(
-                &op,
-                assignations,
-                arguments,
-                span,
-            ))
+            let ident =
+                ident_provider.get_ident_used_in_assignation(&op, assignations, arguments, span);
+
+            ident.map_or(op, Expr::Ident)
         })
     }
 

src/visitor/ident_provider.rs

@@ -18,11 +18,14 @@ pub trait IdentProvider {
         assignations: &mut Vec<Expr>,
         arguments: &mut Vec<Expr>,
         span: &Span,
-    ) -> Ident {
+    ) -> Option<Ident> {
         let id = self.get_temporal_ident_used_in_assignation(operand, assignations, span);
 
         // store ident as argument
-        arguments.push(Expr::Ident(id.clone()));
+        arguments.push(
+            id.as_ref()
+                .map_or_else(|| operand.clone(), |ident| Expr::Ident(ident.clone())),
+        );
 
         id
     }
@@ -32,7 +35,11 @@ pub trait IdentProvider {
         operand: &Expr,
         assignations: &mut Vec<Expr>,
         span: &Span,
-    ) -> Ident {
+    ) -> Option<Ident> {
+        if operand.is_lit() {
+            return None;
+        }
+
         let next_ident = self.next_ident();
         let (assign, id) = self.create_assign_expression(next_ident, operand, span);
 
@@ -41,7 +48,7 @@ pub trait IdentProvider {
 
         assignations.push(Expr::Assign(assign));
 
-        id
+        Some(id)
     }
 
     fn create_assign_expression(

test/string_method.spec.js

@@ -211,10 +211,10 @@ _ddiast.stringSubstring(__datadog_test_1.call(__datadog_test_0, 2), __datadog_te
       rewriteAndExpect(
         js,
         `{
-  let __datadog_test_0, __datadog_test_1, __datadog_test_2;
-(__datadog_test_0 = "hello", __datadog_test_1 = String.prototype.concat, __datadog_test_2 = a, _ddiast.concat(\
-__datadog_test_1.call(__datadog_test_0, __datadog_test_2, "world"), __datadog_test_1, __datadog_test_0, \
-__datadog_test_2, "world"));
+  let __datadog_test_0, __datadog_test_1;
+(__datadog_test_0 = String.prototype.concat, __datadog_test_1 = a, _ddiast.concat(\
+__datadog_test_0.call("hello", __datadog_test_1, "world"), __datadog_test_0, "hello", \
+__datadog_test_1, "world"));
       }`
       )
     })
@@ -241,10 +241,10 @@ __datadog_test_0, "world", null), __datadog_test_1, __datadog_test_0, "world", n
       rewriteAndExpect(
         js,
         `{
-  let __datadog_test_0, __datadog_test_1, __datadog_test_2;
-(__datadog_test_0 = "hello", __datadog_test_1 = String.prototype.concat, __datadog_test_2 = a, \
-_ddiast.concat(__datadog_test_1.call(__datadog_test_0, "world", __datadog_test_2), __datadog_test_1, \
-__datadog_test_0, "world", __datadog_test_2));
+  let __datadog_test_0, __datadog_test_1;
+(__datadog_test_0 = String.prototype.concat, __datadog_test_1 = a, \
+_ddiast.concat(__datadog_test_0.call("hello", "world", __datadog_test_1), __datadog_test_0, \
+"hello", "world", __datadog_test_1));
       }`
       )
     })
@@ -289,9 +289,9 @@ __datadog_test_0, "world", __datadog_test_2));
             const js = builder.build(`return 'a'.${method}(${args});`)
             rewriteAndExpectAndExpectEval(
               js,
-              builder.build(`let __datadog_test_0, __datadog_test_1;
-        return (__datadog_test_0 = 'a', __datadog_test_1 = __datadog_test_0.${method}, _ddiast.${method}(\
-__datadog_test_1.call(__datadog_test_0${argsWithComma}), __datadog_test_1, __datadog_test_0${argsWithComma}));`)
+              builder.build(`let __datadog_test_0;
+        return (__datadog_test_0 = 'a'.${method}, _ddiast.${method}(\
+__datadog_test_0.call('a'${argsWithComma}), __datadog_test_0, 'a'${argsWithComma}));`)
             )
           })
         } else {