feat: deno eval -p (#5682)

cli/flags.rs

@@ -28,6 +28,7 @@ pub enum DenoSubcommand {
     filter: Option<String>,
   },
   Eval {
+    print: bool,
     code: String,
     as_typescript: bool,
   },
@@ -430,7 +431,9 @@ fn eval_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   flags.allow_hrtime = true;
   let code = matches.value_of("code").unwrap().to_string();
   let as_typescript = matches.is_present("ts");
+  let print = matches.is_present("print");
   flags.subcommand = DenoSubcommand::Eval {
+    print,
     code,
     as_typescript,
   }
@@ -744,6 +747,14 @@ This command has implicit access to all permissions (--allow-all).",
         .takes_value(false)
         .multiple(false),
     )
+    .arg(
+      Arg::with_name("print")
+        .long("print")
+        .short("p")
+        .help("print result to stdout")
+        .takes_value(false)
+        .multiple(false),
+    )
     .arg(Arg::with_name("code").takes_value(true).required(true))
     .arg(v8_flags_arg())
 }
@@ -1693,6 +1704,7 @@ mod tests {
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Eval {
+          print: false,
           code: "'console.log(\"hello\")'".to_string(),
           as_typescript: false,
         },
@@ -1708,6 +1720,29 @@ mod tests {
     );
   }
 
+  #[test]
+  fn eval_p() {
+    let r = flags_from_vec_safe(svec!["deno", "eval", "-p", "1+2"]);
+    assert_eq!(
+      r.unwrap(),
+      Flags {
+        subcommand: DenoSubcommand::Eval {
+          print: true,
+          code: "1+2".to_string(),
+          as_typescript: false,
+        },
+        allow_net: true,
+        allow_env: true,
+        allow_run: true,
+        allow_read: true,
+        allow_write: true,
+        allow_plugin: true,
+        allow_hrtime: true,
+        ..Flags::default()
+      }
+    );
+  }
+
   #[test]
   fn eval_unstable() {
     let r = flags_from_vec_safe(svec![
@@ -1721,6 +1756,7 @@ mod tests {
       Flags {
         unstable: true,
         subcommand: DenoSubcommand::Eval {
+          print: false,
           code: "'console.log(\"hello\")'".to_string(),
           as_typescript: false,
         },
@@ -1748,6 +1784,7 @@ mod tests {
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Eval {
+          print: false,
           code: "'console.log(\"hello\")'".to_string(),
           as_typescript: true,
         },
@@ -1771,6 +1808,7 @@ mod tests {
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Eval {
+          print: false,
           code: "42".to_string(),
           as_typescript: false,
         },
@@ -2456,6 +2494,7 @@ mod tests {
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Eval {
+          print: false,
           code: "console.log('hello world')".to_string(),
           as_typescript: false,
         },
@@ -2484,6 +2523,7 @@ mod tests {
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Eval {
+          print: false,
           code: "const foo = 'bar'".to_string(),
           as_typescript: false,
         },

cli/main.rs

@@ -333,6 +333,7 @@ async fn eval_command(
   flags: Flags,
   code: String,
   as_typescript: bool,
+  print: bool,
 ) -> Result<(), ErrBox> {
   // Force TypeScript compile.
   let main_module =
@@ -341,6 +342,13 @@ async fn eval_command(
   let mut worker = MainWorker::create(global_state, main_module.clone())?;
   let main_module_url = main_module.as_url().to_owned();
   // Create a dummy source file.
+  let source_code = if print {
+    "console.log(".to_string() + &code + ")"
+  } else {
+    code.clone()
+  }
+  .into_bytes();
+
   let source_file = SourceFile {
     filename: main_module_url.to_file_path().unwrap(),
     url: main_module_url,
@@ -351,7 +359,7 @@ async fn eval_command(
     } else {
       MediaType::JavaScript
     },
-    source_code: code.clone().into_bytes(),
+    source_code,
   };
   // Save our fake file into file fetcher cache
   // to allow module access by TS compiler (e.g. op_fetch_source_files)
@@ -627,9 +635,10 @@ pub fn main() {
       filter,
     } => doc_command(flags, source_file, json, filter).boxed_local(),
     DenoSubcommand::Eval {
+      print,
       code,
       as_typescript,
-    } => eval_command(flags, code, as_typescript).boxed_local(),
+    } => eval_command(flags, code, as_typescript, print).boxed_local(),
     DenoSubcommand::Cache { files } => {
       cache_command(flags, files).boxed_local()
     }

cli/tests/integration_tests.rs

@@ -53,6 +53,23 @@ fn x_deno_warning() {
   drop(g);
 }
 
+#[test]
+fn eval_p() {
+  let output = util::deno_cmd()
+    .arg("eval")
+    .arg("-p")
+    .arg("1+2")
+    .stdout(std::process::Stdio::piped())
+    .spawn()
+    .unwrap()
+    .wait_with_output()
+    .unwrap();
+  assert!(output.status.success());
+  let stdout_str =
+    util::strip_ansi_codes(std::str::from_utf8(&output.stdout).unwrap().trim());
+  assert_eq!("3", stdout_str);
+}
+
 #[test]
 fn no_color() {
   let output = util::deno_cmd()