Verify if a package was compiled during the mismatch check.

CHANGELOG.md

@@ -24,6 +24,8 @@
 
 #### :nail_care: Polish
 
+- Keep track of compiler info during build. https://github.com/rescript-lang/rescript/pull/7889
+
 #### :house: Internal
 
 # 12.0.0-beta.12

rewatch/src/build.rs

@@ -147,23 +147,30 @@ pub fn initialize_build(
 
     let compiler_check = verify_compiler_info(&packages, &compiler);
 
-    if !snapshot_output && show_progress {
-        println!(
-            "{}{} {}Built package tree in {:.2}s",
-            LINE_CLEAR,
-            style("[1/7]").bold().dim(),
-            TREE,
-            default_timing
-                .unwrap_or(timing_package_tree_elapsed)
-                .as_secs_f64()
-        );
-        if let CompilerCheckResult::CleanedPackagesDueToCompiler = compiler_check {
+    if show_progress {
+        if snapshot_output {
+            if let CompilerCheckResult::CleanedPackagesDueToCompiler = compiler_check {
+                // Snapshot-friendly output (no progress prefixes or emojis)
+                println!("Cleaned previous build due to compiler update");
+            }
+        } else {
             println!(
-                "{}{} {}Cleaned previous build due to compiler update",
+                "{}{} {}Built package tree in {:.2}s",
                 LINE_CLEAR,
                 style("[1/7]").bold().dim(),
-                SWEEP
+                TREE,
+                default_timing
+                    .unwrap_or(timing_package_tree_elapsed)
+                    .as_secs_f64()
             );
+            if let CompilerCheckResult::CleanedPackagesDueToCompiler = compiler_check {
+                println!(
+                    "{}{} {}Cleaned previous build due to compiler update",
+                    LINE_CLEAR,
+                    style("[1/7]").bold().dim(),
+                    SWEEP
+                );
+            }
         }
     }
 

rewatch/src/build/compiler_info.rs

@@ -1,8 +1,8 @@
 use crate::helpers;
 
 use super::build_types::{BuildState, CompilerInfo};
-use super::clean;
 use super::packages;
+use super::{clean, logs};
 use ahash::AHashMap;
 use rayon::prelude::*;
 use serde::{Deserialize, Serialize};
@@ -40,8 +40,9 @@ pub fn verify_compiler_info(
         .filter(|package| {
             let info_path = package.get_compiler_info_path();
             let Ok(contents) = std::fs::read_to_string(&info_path) else {
-                // Can't read file → treat as mismatch so we clean and rewrite
-                return true;
+                // Can't read the compiler-info.json file, maybe there is no current build.
+                // We check if the ocaml build folder exists, if not, we assume the compiler is not installed
+                return logs::does_ocaml_build_compiler_log_exist(package);
             };
 
             let parsed: Result<CompilerInfoFile, _> = serde_json::from_str(&contents);

rewatch/src/build/logs.rs

@@ -24,6 +24,10 @@ fn get_log_file_path(package: &packages::Package, subfolder: Location) -> PathBu
     build_folder.join(".compiler.log")
 }
 
+pub fn does_ocaml_build_compiler_log_exist(package: &packages::Package) -> bool {
+    get_log_file_path(package, Location::Ocaml).exists()
+}
+
 fn escape_colours(str: &str) -> String {
     let re = Regex::new(r"[\u001b\u009b]\[[()#;?]*(?:[0-9]{1,4}(?:;[0-9]{0,4})*)?[0-9A-ORZcf-nqry=><]")
         .expect("Could not create regex");

rewatch/tests/clean.sh

@@ -116,4 +116,42 @@ else
   error "Expected 0 files in node_modules/rescript-nodejs/lib/ocaml after clean, got $compiler_assets"
   printf "%s\n" "$error_output"
   exit 1
-fi
+fi
+
+# If we clean a package, we should not see a "Cleaned previous build due to compiler update" message.
+# Clean the whole repo and rebuild, then ensure the compiler-update clean message is absent
+bold "Test: Clean repo then rebuild should not log compiler update clean"
+
+# Clean repo
+error_output=$(rewatch clean 2>&1)
+if [ $? -eq 0 ];
+then
+  success "Repo Cleaned"
+else
+  error "Error Cleaning Repo"
+  printf "%s\n" "$error_output" >&2
+  exit 1
+fi
+
+# Rebuild with snapshot output
+snapshot_file=../tests/snapshots/clean-rebuild.txt
+rewatch build --snapshot-output &> $snapshot_file
+build_status=$?
+normalize_paths $snapshot_file
+if [ $build_status -eq 0 ];
+then
+  success "Repo Built"
+else
+  error "Error Building Repo"
+  cat $snapshot_file >&2
+  exit 1
+fi
+
+# Verify the undesired message is NOT present
+if grep -q "Cleaned previous build due to compiler update" $snapshot_file; then
+  error "Unexpected compiler-update clean message present in rebuild logs"
+  cat $snapshot_file >&2
+  exit 1
+else
+  success "No compiler-update clean message present after explicit clean"
+fi

rewatch/tests/snapshots/clean-rebuild.txt

@@ -0,0 +1,12 @@
+Cleaned 0/0
+Parsed 112 source files
+Compiled 112 modules
+
+The field 'bs-dependencies' found in the package config of '@testrepo/deprecated-config' is deprecated and will be removed in a future version.
+Use 'dependencies' instead.
+
+The field 'bs-dev-dependencies' found in the package config of '@testrepo/deprecated-config' is deprecated and will be removed in a future version.
+Use 'dev-dependencies' instead.
+
+The field 'bsc-flags' found in the package config of '@testrepo/deprecated-config' is deprecated and will be removed in a future version.
+Use 'compiler-flags' instead.