From 24f91aa1b4ac31d23ce940df786700f0ce57acf9 Mon Sep 17 00:00:00 2001
From: ssube <seansube@gmail.com>
Date: Sat, 15 Jun 2019 19:35:30 -0500
Subject: [PATCH] feat(config): stream type for bunyan config

---
 docs/example-config.yml   |  5 +++++
 src/config/index.ts       |  2 ++
 src/config/type/Stream.ts | 23 +++++++++++++++++++++++
 3 files changed, 30 insertions(+)
 create mode 100644 docs/example-config.yml
 create mode 100644 src/config/type/Stream.ts

diff --git a/docs/example-config.yml b/docs/example-config.yml
new file mode 100644
index 0000000..16d77c6
--- /dev/null
+++ b/docs/example-config.yml
@@ -0,0 +1,5 @@
+data:
+  logger:
+    level: debug
+    name: salty-dog
+    stream: !stream stderr
diff --git a/src/config/index.ts b/src/config/index.ts
index 4e3c496..c73f035 100644
--- a/src/config/index.ts
+++ b/src/config/index.ts
@@ -7,6 +7,7 @@ import { promisify } from 'util';
 import { envType } from 'src/config/type/Env';
 import { includeSchema, includeType } from 'src/config/type/Include';
 import { regexpType } from 'src/config/type/Regexp';
+import { streamType } from 'src/config/type/Stream';
 import { NotFoundError } from 'src/error/NotFoundError';
 
 export const CONFIG_ENV = 'SALTY_HOME';
@@ -14,6 +15,7 @@ export const CONFIG_SCHEMA = Schema.create([DEFAULT_SAFE_SCHEMA], [
   envType,
   includeType,
   regexpType,
+  streamType,
 ]);
 
 includeSchema.schema = CONFIG_SCHEMA;
diff --git a/src/config/type/Stream.ts b/src/config/type/Stream.ts
new file mode 100644
index 0000000..6d28626
--- /dev/null
+++ b/src/config/type/Stream.ts
@@ -0,0 +1,23 @@
+import { Type as YamlType } from 'js-yaml';
+
+import { NotFoundError } from 'src/error/NotFoundError';
+
+const ALLOWED_STREAMS = new Set([
+  'stdout',
+  'stderr',
+]);
+
+export const streamType = new YamlType('!stream', {
+  kind: 'scalar',
+  resolve(name: string) {
+    if (ALLOWED_STREAMS.has(name) && Reflect.has(process, name)) {
+      return true;
+    } else {
+      throw new NotFoundError(`process stream not found: ${name}`);
+    }
+  },
+  construct(name: string) {
+    return Reflect.get(process, name);
+  },
+});
+