From 265be1d6a1f5f34bc09d86f83a9c9f126371c0b4 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 3 Sep 2020 16:35:16 +0200
Subject: [PATCH] config: try to coerce string values into numbers

---
 packages/config-loader/src/loader.test.ts | 21 ---------------------
 packages/config/src/reader.test.ts        |  2 +-
 packages/config/src/reader.ts             | 19 +++++++++++++++++--
 3 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/packages/config-loader/src/loader.test.ts b/packages/config-loader/src/loader.test.ts
index 5246722538..4a7c9f238c 100644
--- a/packages/config-loader/src/loader.test.ts
+++ b/packages/config-loader/src/loader.test.ts
@@ -145,25 +145,4 @@ describe('loadConfig', () => {
       },
     ]);
   });
-
-  it('coerces port to a number', async () => {
-    await expect(
-      loadConfig({
-        rootPaths: ['/secret-port'],
-        env: 'production',
-        shouldReadSecrets: true,
-      }),
-    ).resolves.toEqual([
-      {
-        context: 'app-config.yaml',
-        data: {
-          backend: {
-            listen: {
-              port: 12345,
-            },
-          },
-        },
-      },
-    ]);
-  });
 });
diff --git a/packages/config/src/reader.test.ts b/packages/config/src/reader.test.ts
index 48253dcebe..3fe74aa637 100644
--- a/packages/config/src/reader.test.ts
+++ b/packages/config/src/reader.test.ts
@@ -88,7 +88,7 @@ function expectInvalidValues(config: ConfigReader) {
     "Invalid type in config for key 'string' in 'ctx', got string, wanted boolean",
   );
   expect(() => config.getNumber('string')).toThrow(
-    "Invalid type in config for key 'string' in 'ctx', got string, wanted number",
+    "Unable to convert config value for key 'string' in 'ctx' to a number",
   );
   expect(() => config.getString('one')).toThrow(
     "Invalid type in config for key 'one' in 'ctx', got number, wanted string",
diff --git a/packages/config/src/reader.ts b/packages/config/src/reader.ts
index 65143bbd95..eb8c91e366 100644
--- a/packages/config/src/reader.ts
+++ b/packages/config/src/reader.ts
@@ -49,6 +49,9 @@ const errors = {
   missing(key: string) {
     return `Missing required config value at '${key}'`;
   },
+  convert(key: string, context: string, expected: string) {
+    return `Unable to convert config value for key '${key}' in '${context}' to a ${expected}`;
+  },
 };
 
 export class ConfigReader implements Config {
@@ -183,10 +186,22 @@ export class ConfigReader implements Config {
   }
 
   getOptionalNumber(key: string): number | undefined {
-    return this.readConfigValue(
+    const value = this.readConfigValue<string | number>(
       key,
-      value => typeof value === 'number' || { expected: 'number' },
+      val =>
+        typeof val === 'number' ||
+        typeof val === 'string' || { expected: 'number' },
     );
+    if (typeof value === 'number' || value === undefined) {
+      return value;
+    }
+    const number = Number(value);
+    if (!Number.isFinite(number)) {
+      throw new Error(
+        errors.convert(this.fullKey(key), this.context, 'number'),
+      );
+    }
+    return number;
   }
 
   getBoolean(key: string): boolean {