Export env functions for test and add log

src/env.ts

@@ -9,13 +9,16 @@ const FILE_EXT = '__FILE'
 // Read from env or file
 export async function read_env(key: string): Promise<Ok<string | undefined>> {
   const path = process.env[key + FILE_EXT]
-  if (path !== undefined) return from_file(path)
-  else return {ok: true, data: process.env[key]}
+  if (path !== undefined) {
+    log.debug(`Read ${key} from a file`)
+    log.trace('Path :', path)
+    return from_file(path)
+  } else {
+    log.debug(`Read ${key} from env`)
+    return {ok: true, data: process.env[key]}
+  }
 }
-async function from_file(path: string): Promise<Ok<string>> {
-  log.debug('Read a key from a file')
-  log.trace('Path :', path)
-
+export async function from_file(path: string): Promise<Ok<string>> {
   const content = await get_file_content(path)
   if (!content.ok) return content
 
@@ -23,7 +26,7 @@ async function from_file(path: string): Promise<Ok<string>> {
 
   return content
 }
-async function get_file_content(path: string): Promise<Ok<string>> {
+export async function get_file_content(path: string): Promise<Ok<string>> {
   log.debug('Read file content')
   log.trace('Path :', path)