Merge pull request #278 from kwonoj/fix-issues-277

Author: kwonoj

Cargo.lock

@@ -12,7 +12,7 @@ resolver = "2"
 #lto = true
 
   [workspace.dependencies]
-  istanbul-oxide          = { path = "./packages/istanbul-oxide", version = "0.0.30" }
+  istanbul-oxide          = { path = "./packages/istanbul-oxide", version = "0.0.31" }
   swc-coverage-instrument = { path = "./packages/swc-coverage-instrument" }
 
   getrandom          = { version = "0.2.15" }

Cargo.toml

@@ -1,6 +1,6 @@
 {
   "name": "swc-plugin-coverage-instrument",
-  "version": "0.0.30",
+  "version": "0.0.31",
   "description": "SWC coverage instrumentation plugin",
   "main": "./target/wasm32-wasip1/release/swc_plugin_coverage.wasm",
   "napi": {

package-lock.json

@@ -5,7 +5,7 @@ edition     = "2021"
 license     = "MIT"
 name        = "istanbul-oxide"
 repository  = "https://github.com/kwonoj/swc-coverage-instrument"
-version     = "0.0.30"
+version     = "0.0.31"
 
 [dependencies]
 indexmap = { workspace = true, features = ["serde"] }

package.json

@@ -5,7 +5,7 @@ edition     = "2021"
 license     = "MIT"
 name        = "swc-coverage-instrument"
 repository  = "https://github.com/kwonoj/swc-coverage-instrument"
-version     = "0.0.30"
+version     = "0.0.31"
 
 [dependencies]
 istanbul-oxide = { workspace = true }

packages/istanbul-oxide/Cargo.toml

@@ -160,6 +160,20 @@ impl<C: Clone + Comments, S: SourceMapper> VisitMut for CoverageVisitor<C, S> {
                 ModuleItem::ModuleDecl(decl) => self.on_enter(decl),
                 ModuleItem::Stmt(stmt) => self.on_enter(stmt),
             };
+
+            // https://github.com/kwonoj/swc-plugin-coverage-instrument/issues/277
+            // Add statement counter for export const declarations to match istanbul behavior
+            // Istanbul treats export const and export var differently:
+            // - export const: adds statement counter for the export declaration
+            // - export var: only instruments the initializer, no separate export counter
+            if let ModuleItem::ModuleDecl(ModuleDecl::ExportDecl(export_decl)) = &item {
+                if let Decl::Var(var_decl) = &export_decl.decl {
+                    if var_decl.kind == VarDeclKind::Const {
+                        self.mark_prepend_stmt_counter(&export_decl.span);
+                    }
+                }
+            }
+
             item.visit_mut_children_with(self);
 
             new_items.extend(self.before.drain(..).map(|v| ModuleItem::Stmt(v)));

packages/swc-coverage-instrument/Cargo.toml

@@ -5,7 +5,7 @@ edition     = "2021"
 license     = "MIT"
 name        = "swc-plugin-coverage"
 repository  = "https://github.com/kwonoj/swc-coverage-instrument"
-version     = "0.0.30"
+version     = "0.0.31"
 
 [lib]
 crate-type = ["cdylib"]

packages/swc-coverage-instrument/src/visitors/coverage_visitor.rs

@@ -0,0 +1,13 @@
+---
+name: export const statements coverage (issue 277)
+code: |
+  export const sayHi = () => 'hi';
+
+  export const sayHii = () => 'hii';
+instrumentOpts:
+  esModules: true
+tests:
+  - name: export const coverage
+    lines: {'1': 1, '3': 1}
+    statements: {'0': 1, '1': 0, '2': 1, '3': 0}
+    functions: {'0': 0, '1': 0}