Merge pull request #306 from moonbitlang/robust-pre-build

internal: robust pre build

crates/moon/tests/test_cases/mod.rs

@@ -6669,3 +6669,55 @@ fn no_main_just_init() {
         "#]],
     );
 }
+
+#[test]
+fn test_pre_build() {
+    let dir = TestDir::new("pre_build.in");
+    check(
+        &get_stderr_on_success_with_args_and_replace_dir(&dir, ["check"]),
+        expect![[r#"
+            Executed 3 pre-build tasks, now up to date
+            Finished. moon: ran 2 tasks, now up to date
+        "#]],
+    );
+    check(
+        &get_stderr_on_success_with_args_and_replace_dir(&dir, ["build"]),
+        expect![[r#"
+            Warning: [1002]
+               ╭─[$ROOT/src/lib/a.mbt:3:5]
+               │
+             3 │ let resource : String =
+               │     ────┬───  
+               │         ╰───── Warning: Unused toplevel variable 'resource'. Note if the body contains side effect, it will not happen. Use `fn init { .. }` to wrap the effect.
+            ───╯
+            Finished. moon: ran 3 tasks, now up to date
+        "#]],
+    );
+
+    check(
+        &read(&dir.join("src/lib/a.mbt")),
+        expect![[r#"
+        // Generated by `moon tool embed --text`, do not edit.
+
+        let resource : String =
+          #|hello,
+          #|world
+          #|
+    "#]],
+    );
+    let content = read(&dir.join("src/lib/b.mbt"));
+    assert!(content.contains("// Generated by `moon tool embed --binary`, do not edit."));
+    assert!(content.contains(r#"let _b : Bytes = b"\x6d\x6f\x6f\x6e"#));
+    assert!(content.contains(r#"\x0a\x67\x65\x6e\x65\x72\x61\x74\x65"#));
+    check(
+        &read(&dir.join("src/lib/c.mbt")),
+        expect![[r#"
+        // Generated by `moon tool embed --text`, do not edit.
+
+        let _c : String =
+          #|hello,
+          #|world
+          #|
+    "#]],
+    );
+}

crates/moonbuild/src/entry.rs

@@ -286,9 +286,13 @@ fn vis_build_graph(state: &State, moonbuild_opt: &MoonbuildOpt) {
 
 fn run_moon_generate(moonbuild_opt: &MoonbuildOpt, module: &ModuleDB) -> anyhow::Result<i32> {
     let generate_state = crate::generate::load_moon_generate(moonbuild_opt, module)?;
-    let generate_result = n2_simple_run_interface(generate_state, moonbuild_opt)?;
-    render_generate_result(generate_result, moonbuild_opt.quiet)?;
-    Ok(0)
+    if let Some(generate_state) = generate_state {
+        let generate_result = n2_simple_run_interface(generate_state, moonbuild_opt)?;
+        render_generate_result(generate_result, moonbuild_opt.quiet)?;
+        Ok(0)
+    } else {
+        Ok(0)
+    }
 }
 
 fn render_generate_result(result: Option<usize>, quiet: bool) -> anyhow::Result<i32> {

crates/moonbuild/src/generate.rs

@@ -29,7 +29,7 @@ use n2::smallmap::SmallMap;
 pub fn load_moon_generate(
     moonbuild_opt: &MoonbuildOpt,
     module: &ModuleDB,
-) -> anyhow::Result<State> {
+) -> anyhow::Result<Option<State>> {
     let mut graph = n2graph::Graph::default();
     let mut defaults: Vec<FileId> = vec![];
 
@@ -96,8 +96,11 @@ pub fn load_moon_generate(
                 };
 
                 let mut build = Build::new(loc, ins, outs);
+                let moon_bin = std::env::current_exe()?;
                 let command = if command.starts_with(":embed") {
-                    command.replacen(":embed", "moon tool embed", 1).to_string()
+                    command
+                        .replacen(":embed", &format!("{} tool embed", moon_bin.display()), 1)
+                        .to_string()
                 } else {
                     command.to_string()
                 };
@@ -110,6 +113,10 @@ pub fn load_moon_generate(
         }
     }
 
+    if defaults.is_empty() {
+        return Ok(None);
+    }
+
     let mut hashed = n2graph::Hashes::default();
     let common = moonbuild_opt.raw_target_dir.join("common");
     if !common.exists() {
@@ -118,11 +125,11 @@ pub fn load_moon_generate(
     let _lock = FileLock::lock(&common)?;
     let n2_db_path = common.join("generate.db");
     let db = n2::db::open(&n2_db_path, &mut graph, &mut hashed).unwrap();
-    Ok(State {
+    Ok(Some(State {
         graph,
         db,
         hashes: hashed,
         default: defaults,
         pools: SmallMap::default(),
-    })
+    }))
 }