fix(coverage): do not report transpiled files with no lines (#14699)

This commit omits files from the coverage report that have no
lines of code to report coverage for.

Fixes: https://github.com/denoland/deno/issues/14683

cli/tests/integration/coverage_tests.rs

@@ -236,3 +236,76 @@ fn no_snaps_included(test_name: &str, extension: &str) {
 
   assert!(output.status.success());
 }
+
+#[test]
+fn no_transpiled_lines() {
+  let deno_dir = TempDir::new();
+  let tempdir = TempDir::new();
+  let tempdir = tempdir.path().join("cov");
+
+  let status = util::deno_cmd_with_deno_dir(&deno_dir)
+    .current_dir(util::testdata_path())
+    .arg("test")
+    .arg("--quiet")
+    .arg(format!("--coverage={}", tempdir.to_str().unwrap()))
+    .arg("coverage/no_transpiled_lines/")
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::inherit())
+    .status()
+    .unwrap();
+
+  assert!(status.success());
+
+  let output = util::deno_cmd_with_deno_dir(&deno_dir)
+    .current_dir(util::testdata_path())
+    .arg("coverage")
+    .arg(format!("{}/", tempdir.to_str().unwrap()))
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::piped())
+    .output()
+    .unwrap();
+
+  let actual =
+    util::strip_ansi_codes(std::str::from_utf8(&output.stdout).unwrap())
+      .to_string();
+
+  let expected = fs::read_to_string(
+    util::testdata_path().join("coverage/no_transpiled_lines/expected.out"),
+  )
+  .unwrap();
+
+  if !util::wildcard_match(&expected, &actual) {
+    println!("OUTPUT\n{}\nOUTPUT", actual);
+    println!("EXPECTED\n{}\nEXPECTED", expected);
+    panic!("pattern match failed");
+  }
+
+  assert!(output.status.success());
+
+  let output = util::deno_cmd_with_deno_dir(&deno_dir)
+    .current_dir(util::testdata_path())
+    .arg("coverage")
+    .arg("--lcov")
+    .arg(format!("{}/", tempdir.to_str().unwrap()))
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::inherit())
+    .output()
+    .unwrap();
+
+  let actual =
+    util::strip_ansi_codes(std::str::from_utf8(&output.stdout).unwrap())
+      .to_string();
+
+  let expected = fs::read_to_string(
+    util::testdata_path().join("coverage/no_transpiled_lines/expected.lcov"),
+  )
+  .unwrap();
+
+  if !util::wildcard_match(&expected, &actual) {
+    println!("OUTPUT\n{}\nOUTPUT", actual);
+    println!("EXPECTED\n{}\nEXPECTED", expected);
+    panic!("pattern match failed");
+  }
+
+  assert!(output.status.success());
+}

cli/tests/testdata/coverage/no_transpiled_lines/expected.lcov

@@ -0,0 +1,12 @@
+SF:[WILDCARD]index.ts
+FNF:0
+FNH:0
+BRF:0
+BRH:0
+DA:1,1
+DA:2,1
+DA:3,1
+DA:5,1
+LH:4
+LF:4
+end_of_record

cli/tests/testdata/coverage/no_transpiled_lines/expected.out

@@ -0,0 +1 @@
+cover [WILDCARD]index.ts ... 100.000% (4/4)

cli/tests/testdata/coverage/no_transpiled_lines/index.ts

@@ -0,0 +1,5 @@
+export {
+  assertStrictEquals,
+} from "https://deno.land/std@0.139.0/testing/asserts.ts";
+
+export * from "./interface.ts";

cli/tests/testdata/coverage/no_transpiled_lines/interface.ts

@@ -0,0 +1,3 @@
+export interface TestInterface {
+  id: string;
+}

cli/tests/testdata/coverage/no_transpiled_lines/repro_test.ts

@@ -0,0 +1,7 @@
+import { assertStrictEquals, TestInterface } from "./index.ts";
+
+Deno.test(function noTranspiledLines() {
+  const foo: TestInterface = { id: "id" };
+
+  assertStrictEquals(foo.id, "id");
+});

cli/tools/coverage/mod.rs

@@ -703,7 +703,9 @@ pub async fn cover_files(
       &out_mode,
     );
 
-    reporter.report(&coverage_report, original_source)?;
+    if !coverage_report.found_lines.is_empty() {
+      reporter.report(&coverage_report, original_source)?;
+    }
   }
 
   reporter.done();