From c6d357a5e3c6aa6bcf1c5f52eedd2e663a5caaca Mon Sep 17 00:00:00 2001
From: OJ Kwon <1210596+kwonoj@users.noreply.github.com>
Date: Wed, 12 Jul 2023 09:51:44 -0700
Subject: [PATCH] feat(turbopack_core): define trait for diagnostics

---
 crates/turbopack-core/src/diagnostics/mod.rs | 34 ++++++++++++++++++++
 crates/turbopack-core/src/lib.rs             |  1 +
 2 files changed, 35 insertions(+)
 create mode 100644 crates/turbopack-core/src/diagnostics/mod.rs

diff --git a/crates/turbopack-core/src/diagnostics/mod.rs b/crates/turbopack-core/src/diagnostics/mod.rs
new file mode 100644
index 00000000000000..604e9eca33e2a0
--- /dev/null
+++ b/crates/turbopack-core/src/diagnostics/mod.rs
@@ -0,0 +1,34 @@
+use anyhow::Result;
+use turbo_tasks::{emit, primitives::StringVc};
+
+/// An arbitrary metadata payload can be used to analyze, diagnose
+/// Turbopack's behavior.
+#[turbo_tasks::value_trait]
+pub trait Diagnostics {
+    // [TODO]: These are subject to change; not finalized yet.
+    fn category(&self) -> StringVc;
+    fn key(&self) -> StringVc;
+    fn value(&self) -> StringVc;
+}
+
+impl DiagnosticsVc {
+    pub fn emit(self) {
+        emit(self);
+    }
+
+    pub async fn peek_diagnostics_with_path<T: turbo_tasks::CollectiblesSource + Copy>(
+        source: T,
+    ) -> Result<CapturedDiagnosticsVc> {
+        Ok(CapturedDiagnosticsVc::cell(CapturedDiagnostics {
+            diagnostics: source.peek_collectibles().strongly_consistent().await?,
+        }))
+    }
+}
+
+/// A list of diagnostics captured with
+/// [`DiagnosticsVc::peek_diagnostics_with_path`] and
+#[derive(Debug)]
+#[turbo_tasks::value]
+pub struct CapturedDiagnostics {
+    pub diagnostics: auto_hash_map::AutoSet<DiagnosticsVc>,
+}
diff --git a/crates/turbopack-core/src/lib.rs b/crates/turbopack-core/src/lib.rs
index 3c27f998859b89..168a0262ddc905 100644
--- a/crates/turbopack-core/src/lib.rs
+++ b/crates/turbopack-core/src/lib.rs
@@ -11,6 +11,7 @@ pub mod chunk;
 pub mod code_builder;
 pub mod compile_time_info;
 pub mod context;
+pub mod diagnostics;
 pub mod environment;
 pub mod error;
 pub mod file_source;