fix(error-reporters): Store diagnostics in TransformOutput (#10027)

**Related issue:**

 - Closes #9887

bindings/binding_core_wasm/__tests__/simple.js

@@ -1,7 +1,7 @@
 const swc = require("../pkg");
 
 describe("transform", () => {
-    it("should work", function () {
+    it("should work", () => {
         const output = swc.transformSync("class Foo {}", {});
 
         expect(output).toMatchInlineSnapshot(`
@@ -16,6 +16,7 @@ describe("transform", () => {
                 _class_call_check(this, Foo);
             };
             ",
+              "diagnostics": [],
             }
         `);
     });
@@ -35,6 +36,7 @@ describe("transform", () => {
                 _class_call_check(this, Foo);
             };
             ",
+              "diagnostics": [],
             }
         `);
     });
@@ -58,6 +60,7 @@ describe("transform", () => {
                 _class_call_check(this, Foo);
             };
             ",
+              "diagnostics": [],
             }
         `);
     });
@@ -195,6 +198,7 @@ describe("minify", () => {
         expect(output).toMatchInlineSnapshot(`
             {
               "code": "let somename=1;console.log(1);",
+              "diagnostics": [],
             }
         `);
     });
@@ -208,6 +212,7 @@ describe("minify", () => {
         expect(output).toMatchInlineSnapshot(`
             {
               "code": "let somename=1;console.log(1);",
+              "diagnostics": [],
             }
         `);
     });
@@ -226,6 +231,7 @@ describe("print", () => {
               "code": "class Foo {
             }
             ",
+              "diagnostics": [],
             }
         `);
     });
@@ -242,6 +248,7 @@ describe("print", () => {
               "code": "class Foo {
             }
             ",
+              "diagnostics": [],
             }
         `);
     });

bindings/binding_minifier_wasm/__tests__/__snapshots__/simple.js.snap

@@ -3,5 +3,6 @@
 exports[`minify should work 1`] = `
 Object {
   "code": "console.log(1);",
+  "diagnostics": Array [],
 }
 `;

crates/swc/src/lib.rs

@@ -894,7 +894,7 @@ impl Compiler {
                 opts.format.preserve_annotations,
             );
 
-            self.print(
+            let ret = self.print(
                 &program,
                 PrintArgs {
                     source_root: None,
@@ -917,7 +917,13 @@ impl Compiler {
                         .with_inline_script(opts.format.inline_script),
                     output: None,
                 },
-            )
+            );
+
+            ret.map(|mut output| {
+                output.diagnostics = handler.take_diagnostics();
+
+                output
+            })
         })
     }
 

crates/swc_common/src/errors/emitter.rs

@@ -41,6 +41,10 @@ pub trait Emitter: crate::sync::Send {
     fn should_show_explain(&self) -> bool {
         true
     }
+
+    fn take_diagnostics(&mut self) -> Vec<String> {
+        vec![]
+    }
 }
 
 impl Emitter for EmitterWriter {

crates/swc_common/src/errors/mod.rs

@@ -874,6 +874,10 @@ impl Handler {
             }
         }
     }
+
+    pub fn take_diagnostics(&self) -> Vec<String> {
+        self.emitter.borrow_mut().take_diagnostics()
+    }
 }
 
 #[derive(Copy, PartialEq, Eq, Clone, Hash, Debug)]

crates/swc_compiler_base/src/lib.rs

@@ -36,17 +36,22 @@ pub struct TransformOutput {
 
     #[serde(skip_serializing_if = "Option::is_none")]
     pub output: Option<String>,
+
+    pub diagnostics: std::vec::Vec<String>,
 }
 
 #[cfg(not(feature = "node"))]
 #[derive(Debug, Serialize)]
 pub struct TransformOutput {
     pub code: String,
+
     #[serde(skip_serializing_if = "Option::is_none")]
     pub map: Option<String>,
 
     #[serde(skip_serializing_if = "Option::is_none")]
     pub output: Option<String>,
+
+    pub diagnostics: std::vec::Vec<String>,
 }
 
 /// This method parses a javascript / typescript file
@@ -272,6 +277,7 @@ where
         output: output
             .map(|v| serde_json::to_string(&v).context("failed to serilaize output"))
             .transpose()?,
+        diagnostics: Default::default(),
     })
 }
 

crates/swc_error_reporters/src/lib.rs

@@ -23,6 +23,8 @@ pub struct PrettyEmitter {
     reporter: GraphicalReportHandler,
 
     config: PrettyEmitterConfig,
+
+    diagnostics: Vec<String>,
 }
 
 #[derive(Debug, Clone, Default)]
@@ -42,6 +44,7 @@ impl PrettyEmitter {
             wr: WriterWrapper(wr),
             reporter,
             config,
+            diagnostics: vec![],
         }
     }
 }
@@ -175,9 +178,19 @@ impl Emitter for PrettyEmitter {
             children,
         };
 
+        let mut format_result = String::new();
+
         self.reporter
-            .render_report(&mut self.wr, &diagnostic)
+            .render_report(&mut format_result, &diagnostic)
             .unwrap();
+
+        self.diagnostics.push(format_result.clone());
+
+        self.wr.write_str(&format_result).unwrap()
+    }
+
+    fn take_diagnostics(&mut self) -> Vec<String> {
+        std::mem::take(&mut self.diagnostics)
     }
 }