feat(next/swc): support experimental coverage instrument

Author: kwonoj

packages/next-swc/Cargo.lock

@@ -33,6 +33,7 @@ swc_ecma_loader = { version = "0.30.2", features = ["node", "lru"] }
 swc_ecmascript = { version = "0.164.0", features = ["codegen", "minifier", "optimization", "parser", "react", "transforms", "typescript", "utils", "visit"] }
 swc_plugin_runner = { version = "0.56.0", optional = true, default-features = false }
 swc_cached = "0.1.1"
+swc-coverage-instrument = "0.0.7"
 tracing = { version = "0.1.32", features = ["release_max_level_info"] }
 wasmer = { version = "2.3.0", optional = true, default-features = false }
 wasmer-wasi = { version = "2.3.0", optional = true, default-features = false }

packages/next-swc/crates/core/Cargo.toml

@@ -43,7 +43,7 @@ use swc_common::{FileName, SourceFile, SourceMap};
 use swc_ecmascript::ast::EsVersion;
 use swc_ecmascript::parser::parse_file_as_module;
 use swc_ecmascript::transforms::pass::noop;
-use swc_ecmascript::visit::Fold;
+use swc_ecmascript::visit::{as_folder, Fold};
 
 pub mod amp_attributes;
 mod auto_cjs;
@@ -104,9 +104,12 @@ pub struct TransformOptions {
 
     #[serde(default)]
     pub modularize_imports: Option<modularize_imports::Config>,
+
+    #[serde(default)]
+    pub coverage_instrument: Option<swc_coverage_instrument::InstrumentOptions>,
 }
 
-pub fn custom_before_pass<'a, C: Comments + 'a>(
+pub fn custom_before_pass<'a, C: Comments + 'a + std::clone::Clone>(
     cm: Arc<SourceMap>,
     file: Arc<SourceFile>,
     opts: &'a TransformOptions,
@@ -182,8 +185,8 @@ pub fn custom_before_pass<'a, C: Comments + 'a>(
                         Either::Left(swc_emotion::EmotionTransformer::new(
                             config.clone(),
                             path,
-                            cm,
-                            comments,
+                            cm.clone(),
+                            comments.clone(),
                         ))
                     })
                 } else {
@@ -194,7 +197,18 @@ pub fn custom_before_pass<'a, C: Comments + 'a>(
         match &opts.modularize_imports {
             Some(config) => Either::Left(modularize_imports::modularize_imports(config.clone())),
             None => Either::Right(noop()),
-        }
+        },
+        match &opts.coverage_instrument {
+            Some(config) => Either::Left(as_folder(
+                swc_coverage_instrument::create_coverage_instrumentation_visitor(
+                    cm,
+                    comments,
+                    config.clone(),
+                    file.name.to_string()
+                )
+            )),
+            None => Either::Right(noop()),
+        },
     )
 }
 

packages/next-swc/crates/core/src/lib.rs

@@ -10,6 +10,7 @@ use next_swc::{
 };
 use std::path::PathBuf;
 use swc_common::{chain, comments::SingleThreadedComments, FileName, Mark};
+use swc_coverage_instrument::create_coverage_instrumentation_visitor;
 use swc_ecma_transforms_testing::{test, test_fixture};
 use swc_ecmascript::{
     parser::{EsConfig, Syntax},
@@ -209,3 +210,21 @@ fn shake_exports_fixture_default(input: PathBuf) {
         &output,
     );
 }
+
+#[fixture("tests/fixture/coverage-instrument/input.js")]
+fn coverage_instrument_simple_default(input: PathBuf) {
+    let output = input.parent().unwrap().join("output.js");
+    test_fixture(
+        syntax(),
+        &|tr| {
+            swc_ecmascript::visit::as_folder(create_coverage_instrumentation_visitor(
+                tr.cm.clone(),
+                tr.comments.clone(),
+                Default::default(),
+                "anon".to_string(),
+            ))
+        },
+        &input,
+        &output,
+    );
+}

packages/next-swc/crates/core/tests/fixture.rs

@@ -0,0 +1,6 @@
+function* x() { yield 1; yield 2; };
+var k;
+output = 0;
+for (k of x()) {
+  output += k;
+}