feat(cli): add --coverage flag to deno run command (#29329)

closes #16440

This PR adds `--coverage` flag to `deno run` command. When the flag is
specified, it generates the coverage profile in the directory specified
(default is `coverage`). The coverage directory can also be specified
from the env var `DENO_COVERAGE_DIR`.

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

cli/args/flags.rs

@@ -336,6 +336,7 @@ pub struct RunFlags {
   pub script: String,
   pub watch: Option<WatchFlagsWithPaths>,
   pub bare: bool,
+  pub coverage_dir: Option<String>,
 }
 
 impl RunFlags {
@@ -345,6 +346,7 @@ impl RunFlags {
       script,
       watch: None,
       bare: false,
+      coverage_dir: None,
     }
   }
 
@@ -3306,6 +3308,7 @@ fn run_args(command: Command, top_level: bool) -> Command {
     })
     .arg(env_file_arg())
     .arg(no_code_cache_arg())
+    .arg(coverage_arg())
 }
 
 fn run_subcommand() -> Command {
@@ -4475,6 +4478,21 @@ fn no_code_cache_arg() -> Arg {
     .action(ArgAction::SetTrue)
 }
 
+fn coverage_arg() -> Arg {
+  Arg::new("coverage")
+    .long("coverage")
+    .value_name("DIR")
+    .num_args(0..=1)
+    .require_equals(true)
+    .default_missing_value("coverage")
+    .conflicts_with("inspect")
+    .conflicts_with("inspect-wait")
+    .conflicts_with("inspect-brk")
+    .help(cstr!("Collect coverage profile data into DIR. If DIR is not specified, it uses 'coverage/'.
+  <p(245)>This option can also be set via the DENO_COVERAGE_DIR environment variable."))
+    .value_hint(ValueHint::AnyPath)
+}
+
 fn permit_no_files_arg() -> Arg {
   Arg::new("permit-no-files")
     .long("permit-no-files")
@@ -5600,6 +5618,7 @@ fn run_parse(
   ext_arg_parse(flags, matches);
 
   flags.code_cache_enabled = !matches.get_flag("no-code-cache");
+  let coverage_dir = matches.remove_one::<String>("coverage");
 
   if let Some(mut script_arg) = matches.remove_many::<String>("script_arg") {
     let script = script_arg.next().unwrap();
@@ -5608,6 +5627,7 @@ fn run_parse(
       script,
       watch: watch_arg_parse_with_paths(matches)?,
       bare,
+      coverage_dir,
     });
   } else if bare {
     return Err(app.override_usage("deno [OPTIONS] [COMMAND] [SCRIPT_ARG]...").error(
@@ -6566,6 +6586,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6591,6 +6612,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: true,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6617,6 +6639,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6643,6 +6666,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6669,6 +6693,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6696,6 +6721,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: true,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6726,6 +6752,7 @@ mod tests {
             exclude: vec![],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6755,6 +6782,7 @@ mod tests {
             exclude: vec![String::from("foo")],
           }),
           bare: true,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6781,6 +6809,7 @@ mod tests {
             exclude: vec![String::from("bar")],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6808,6 +6837,7 @@ mod tests {
             exclude: vec![String::from("foo"), String::from("bar")],
           }),
           bare: false,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6834,6 +6864,7 @@ mod tests {
             exclude: vec![String::from("baz"), String::from("qux"),],
           }),
           bare: true,
+          coverage_dir: None,
         }),
         code_cache_enabled: true,
         ..Flags::default()
@@ -6862,6 +6893,24 @@ mod tests {
     );
   }
 
+  #[test]
+  fn run_coverage() {
+    let r = flags_from_vec(svec!["deno", "run", "--coverage=foo", "script.ts"]);
+    assert_eq!(
+      r.unwrap(),
+      Flags {
+        subcommand: DenoSubcommand::Run(RunFlags {
+          script: "script.ts".to_string(),
+          watch: None,
+          bare: false,
+          coverage_dir: Some("foo".to_string()),
+        }),
+        code_cache_enabled: true,
+        ..Flags::default()
+      }
+    );
+  }
+
   #[test]
   fn run_v8_flags() {
     let r = flags_from_vec(svec!["deno", "run", "--v8-flags=--help"]);
@@ -7170,6 +7219,7 @@ mod tests {
           script: "gist.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         permissions: PermissionFlags {
           deny_read: Some(vec![]),
@@ -8456,6 +8506,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         permissions: PermissionFlags {
           deny_net: Some(svec!["127.0.0.1"]),
@@ -8643,6 +8694,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         permissions: PermissionFlags {
           deny_sys: Some(svec!["hostname"]),
@@ -8942,6 +8994,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         ..Flags::default()
       }
@@ -9252,6 +9305,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         log_level: Some(Level::Error),
         code_cache_enabled: true,
@@ -9372,6 +9426,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         type_check_mode: TypeCheckMode::None,
         code_cache_enabled: true,
@@ -9540,6 +9595,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         node_modules_dir: Some(NodeModulesDirMode::Auto),
         code_cache_enabled: true,
@@ -10763,6 +10819,7 @@ mod tests {
           script: "foo.js".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         inspect_wait: Some("127.0.0.1:9229".parse().unwrap()),
         code_cache_enabled: true,
@@ -11453,6 +11510,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         type_check_mode: TypeCheckMode::None,
         code_cache_enabled: true,
@@ -12006,6 +12064,7 @@ mod tests {
           script: "script.ts".to_string(),
           watch: None,
           bare: true,
+          coverage_dir: None,
         }),
         config_flag: ConfigFlag::Disabled,
         code_cache_enabled: true,

cli/args/mod.rs

@@ -762,6 +762,11 @@ impl CliOptions {
         .as_ref()
         .map(ToOwned::to_owned)
         .or_else(|| env::var("DENO_COVERAGE_DIR").ok()),
+      DenoSubcommand::Run(flags) => flags
+        .coverage_dir
+        .as_ref()
+        .map(ToOwned::to_owned)
+        .or_else(|| env::var("DENO_COVERAGE_DIR").ok()),
       _ => None,
     }
   }

cli/tools/coverage/mod.rs

@@ -579,6 +579,7 @@ fn filter_coverages(
         || e.url.starts_with("data:")
         || e.url.ends_with("__anonymous__")
         || e.url.ends_with("$deno$test.mjs")
+        || e.url.ends_with("$deno$stdin.mts")
         || e.url.ends_with(".snap")
         || is_supported_test_path(Path::new(e.url.as_str()))
         || doc_test_re.is_match(e.url.as_str())

cli/tools/deploy.rs

@@ -37,6 +37,7 @@ pub async fn deploy(
     ),
     watch: None,
     bare: false,
+    coverage_dir: None,
   });
 
   tools::run::run_script(

tests/specs/run/run_coverage/__test__.jsonc

@@ -0,0 +1,36 @@
+{
+  "tempDir": true,
+  "tests": {
+    "run_coverage": {
+      "steps": [
+        {
+          "args": "run --coverage foo.ts",
+          "output": "0\n0\n"
+        },
+        {
+          "args": "coverage",
+          "output": "coverage_summary.out"
+        }
+      ]
+    },
+    "run_coverage_env": {
+      "steps": [
+        {
+          "args": "run foo.ts",
+          "output": "0\n0\n",
+          "envs": {
+            "DENO_COVERAGE_DIR": "my_coverage_dir"
+          }
+        },
+        {
+          "args": "coverage my_coverage_dir",
+          "output": "coverage_summary.out"
+        }
+      ]
+    },
+    "test_child_process_coverage": {
+      "args": "test -A --coverage child_process_coverage_test.ts",
+      "output": "child_process_coverage_test.out"
+    }
+  }
+}

tests/specs/run/run_coverage/child_process_coverage_test.out

@@ -0,0 +1,13 @@
+Check file:///[WILDLINE]child_process_coverage_test.ts
+running 2 tests from ./child_process_coverage_test.ts
+foo 1 0 ... ok ([WILDLINE]s)
+foo 0 1 ... ok ([WILDLINE]s)
+
+ok | 2 passed | 0 failed ([WILDLINE]s)
+
+| File      | Branch % | Line % |
+| --------- | -------- | ------ |
+| foo.ts    |    100.0 |  100.0 |
+| All files |    100.0 |  100.0 |
+Lcov coverage report has been generated at file:///[WILDLINE]/coverage/lcov.info
+HTML coverage report has been generated at file:///[WILDLINE]/coverage/html/index.html

tests/specs/run/run_coverage/child_process_coverage_test.ts

@@ -0,0 +1,6 @@
+Deno.test("foo 1 0", () => runDenoCommand("run foo.ts 1 0"));
+Deno.test("foo 0 1", () => runDenoCommand("run foo.ts 0 1"));
+
+async function runDenoCommand(args: string) {
+  await new Deno.Command(Deno.execPath(), { args: args.split(" ") }).output();
+}

tests/specs/run/run_coverage/coverage_summary.out

@@ -0,0 +1,4 @@
+| File      | Branch % | Line % |
+| --------- | -------- | ------ |
+| foo.ts    |      0.0 |   57.1 |
+| All files |      0.0 |   57.1 |

tests/specs/run/run_coverage/foo.ts

@@ -0,0 +1,17 @@
+function foo(a: number, b: number) {
+  if (a > 0) {
+    console.log(a);
+  } else {
+    console.log(a);
+  }
+
+  if (b > 0) {
+    console.log(b);
+  } else {
+    console.log(b);
+  }
+}
+
+const [a = 0, b = 0] = Deno.args;
+
+foo(+a, +b);