fix(coverage): merge coverage ranges (#13334)

Covered ranges were not merged and thus it appeared that some lines
might be uncovered. To fix this I used "v8-coverage" that takes care
of merging the ranges properly. With this change, coverage collected
from a file by multiple entrypoints is now correctly calculated.

I ended up forking https://github.com/demurgos/v8-coverage and adding
"cli/tools/coverage/merge.rs" and "cli/tools/coverage/range_tree.rs".

6 files changed, 121 insertions, 0 deletions

diff --git a/cli/tests/integration/coverage_tests.rs b/cli/tests/integration/coverage_tests.rs
index 637185e29..e6eb5fe3a 100644
--- a/cli/tests/integration/coverage_tests.rs
+++ b/cli/tests/integration/coverage_tests.rs
@@ -97,3 +97,83 @@ fn run_coverage_text(test_name: &str, extension: &str) {
 
   assert!(output.status.success());
 }
+
+#[test]
+fn multifile_coverage() {
+  let deno_dir = TempDir::new().expect("tempdir fail");
+  let tempdir = TempDir::new().expect("tempdir fail");
+  let tempdir = tempdir.path().join("cov");
+
+  let status = util::deno_cmd_with_deno_dir(deno_dir.path())
+    .current_dir(util::testdata_path())
+    .arg("test")
+    .arg("--quiet")
+    .arg("--unstable")
+    .arg(format!("--coverage={}", tempdir.to_str().unwrap()))
+    .arg("coverage/multifile/")
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::inherit())
+    .status()
+    .expect("failed to spawn test runner");
+
+  assert!(status.success());
+
+  let output = util::deno_cmd_with_deno_dir(deno_dir.path())
+    .current_dir(util::testdata_path())
+    .arg("coverage")
+    .arg("--unstable")
+    .arg(format!("{}/", tempdir.to_str().unwrap()))
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::piped())
+    .output()
+    .expect("failed to spawn coverage reporter");
+
+  // Verify there's no "Check" being printed
+  assert!(output.stderr.is_empty());
+
+  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/multifile/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.path())
+    .current_dir(util::testdata_path())
+    .arg("coverage")
+    .arg("--quiet")
+    .arg("--unstable")
+    .arg("--lcov")
+    .arg(format!("{}/", tempdir.to_str().unwrap()))
+    .stdout(std::process::Stdio::piped())
+    .stderr(std::process::Stdio::inherit())
+    .output()
+    .expect("failed to spawn coverage reporter");
+
+  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/multifile/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());
+}
diff --git a/cli/tests/testdata/coverage/multifile/a_test.js b/cli/tests/testdata/coverage/multifile/a_test.js
new file mode 100644
index 000000000..d5d9c3533
--- /dev/null
+++ b/cli/tests/testdata/coverage/multifile/a_test.js
@@ -0,0 +1,8 @@
+import { test } from "./mod.js";
+
+Deno.test({
+  name: "bugrepo a",
+  fn: () => {
+    test(true);
+  },
+});
diff --git a/cli/tests/testdata/coverage/multifile/b_test.js b/cli/tests/testdata/coverage/multifile/b_test.js
new file mode 100644
index 000000000..d93b15a17
--- /dev/null
+++ b/cli/tests/testdata/coverage/multifile/b_test.js
@@ -0,0 +1,8 @@
+import { test } from "./mod.js";
+
+Deno.test({
+  name: "bugrepo b",
+  fn: () => {
+    test(false);
+  },
+});
diff --git a/cli/tests/testdata/coverage/multifile/expected.lcov b/cli/tests/testdata/coverage/multifile/expected.lcov
new file mode 100644
index 000000000..03ad5e7bd
--- /dev/null
+++ b/cli/tests/testdata/coverage/multifile/expected.lcov
@@ -0,0 +1,18 @@
+SF:[WILDCARD]mod.js
+FN:1,test
+FNDA:2,test
+FNF:1
+FNH:1
+BRDA:2,1,0,1
+BRF:1
+BRH:1
+DA:1,2
+DA:2,4
+DA:3,5
+DA:4,5
+DA:5,5
+DA:6,4
+DA:7,1
+LH:7
+LF:7
+end_of_record
diff --git a/cli/tests/testdata/coverage/multifile/expected.out b/cli/tests/testdata/coverage/multifile/expected.out
new file mode 100644
index 000000000..fde26e165
--- /dev/null
+++ b/cli/tests/testdata/coverage/multifile/expected.out
@@ -0,0 +1 @@
+cover [WILDCARD]/multifile/mod.js ... 100.000% (7/7)
diff --git a/cli/tests/testdata/coverage/multifile/mod.js b/cli/tests/testdata/coverage/multifile/mod.js
new file mode 100644
index 000000000..b9f8d627a
--- /dev/null
+++ b/cli/tests/testdata/coverage/multifile/mod.js
@@ -0,0 +1,6 @@
+export function test(a) {
+  if (a) {
+    return 0;
+  }
+  return 1;
+}