[Openapi-Diff] Bump autorest to ^3.8.0 and fix stderr handling

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.12.4 2026-03-13
+
+- Only throw error on AutoRest stderr when exit code is non-zero; log warnings otherwise
+
 # 0.12.3 2025-10-13
 
 - Fix crash in logging when property named "$ref"

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@azure/oad",
-  "version": "0.12.3",
+  "version": "0.12.4",
   "author": {
     "name": "Microsoft Corporation",
     "email": "azsdkteam@microsoft.com",
@@ -15,7 +15,7 @@
     "@ts-common/json-parser": "0.9.0",
     "@ts-common/source-map": "0.5.0",
     "@ts-common/string-map": "0.3.0",
-    "autorest": "^3.6.1",
+    "autorest": "^3.8.0",
     "js-yaml": "^4.1.0",
     "json-pointer": "0.6.2",
     "json-refs": "^3.0.15",

src/lib/validators/openApiDiff.ts

@@ -244,13 +244,20 @@ export class OpenApiDiff {
 
     log.debug(`Executing: "${autoRestFile} ${args.join(" ")}"`)
 
-    const { stderr } = await execFile(autoRestFile, args, {
-      encoding: "utf8",
-      maxBuffer: 1024 * 1024 * 64,
-      env: { ...process.env, NODE_OPTIONS: "--max-old-space-size=8192" }
-    })
+    // autorest 3.8.0 emits deprecation message to stderr with exit code 0
+    let stderr: string
+    try {
+      const result = await execFile(autoRestFile, args, {
+        encoding: "utf8",
+        maxBuffer: 1024 * 1024 * 64,
+        env: { ...process.env, NODE_OPTIONS: "--max-old-space-size=8192" }
+      })
+      stderr = result.stderr
+    } catch (e) {
+      throw new Error(util.inspect(e))
+    }
     if (stderr) {
-      throw new Error(stderr)
+      log.error(`AutoRest completed with warnings on stderr: ${stderr}`)
     }
 
     const buffer = await asyncFs.readFile(outputMapFilePath)