fix(es/minifier): Mark usage in TaggedTpl as ref

crates/swc_ecma_minifier/tests/fixture/issues/8974/config.json

@@ -0,0 +1,47 @@
+{
+    "defaults": true,
+    "arguments": false,
+    "arrows": true,
+    "booleans": true,
+    "booleans_as_integers": false,
+    "collapse_vars": true,
+    "comparisons": true,
+    "computed_props": true,
+    "conditionals": true,
+    "dead_code": true,
+    "directives": true,
+    "drop_console": false,
+    "drop_debugger": true,
+    "evaluate": true,
+    "expression": false,
+    "hoist_funs": false,
+    "hoist_props": true,
+    "hoist_vars": false,
+    "if_return": true,
+    "join_vars": true,
+    "keep_classnames": false,
+    "keep_fargs": true,
+    "keep_fnames": false,
+    "keep_infinity": false,
+    "loops": true,
+    "negate_iife": true,
+    "properties": true,
+    "reduce_funcs": false,
+    "reduce_vars": false,
+    "side_effects": true,
+    "switches": true,
+    "typeofs": true,
+    "unsafe": false,
+    "unsafe_arrows": false,
+    "unsafe_comps": false,
+    "unsafe_Function": false,
+    "unsafe_math": false,
+    "unsafe_symbols": false,
+    "unsafe_methods": false,
+    "unsafe_proto": false,
+    "unsafe_regexp": false,
+    "unsafe_undefined": false,
+    "unused": true,
+    "const_to_let": true,
+    "pristine_globals": true
+}

crates/swc_ecma_minifier/tests/fixture/issues/8974/input.js

@@ -0,0 +1,13 @@
+const one = {
+    kind: "Document",
+    definitions: [],
+    loc: {}
+};
+const two = {
+    kind: "Document",
+    definitions: one.definitions,
+};
+
+const three = a`${one}`;
+
+export { }

crates/swc_ecma_minifier/tests/fixture/issues/8974/output.js

@@ -0,0 +1,7 @@
+const one = {
+    kind: "Document",
+    definitions: [],
+    loc: {}
+};
+one.definitions, a`${one}`;
+export { };

crates/swc_ecma_usage_analyzer/src/analyzer/mod.rs

@@ -1168,12 +1168,24 @@ where
 
     #[cfg_attr(feature = "debug", tracing::instrument(skip_all))]
     fn visit_tagged_tpl(&mut self, n: &TaggedTpl) {
-        let ctx = Ctx {
-            is_id_ref: false,
-            ..self.ctx
-        };
+        {
+            let ctx = Ctx {
+                is_id_ref: false,
+                ..self.ctx
+            };
 
-        n.visit_children_with(&mut *self.with_ctx(ctx))
+            n.tag.visit_with(&mut *self.with_ctx(ctx));
+        }
+
+        {
+            let ctx = Ctx {
+                is_id_ref: true,
+                ..self.ctx
+            };
+
+            // Bypass visit_tpl
+            n.tpl.visit_children_with(&mut *self.with_ctx(ctx))
+        }
     }
 
     #[cfg_attr(feature = "debug", tracing::instrument(skip_all))]