feat: reads env from parsing context

Author: joelgallant

app-config-core/src/parsed-value.ts

@@ -17,7 +17,7 @@ export type ParsingExtensionKey =
   | [typeof InArray, number]
   | [typeof Root];
 
-export type ParsingContext = Record<string, string>;
+export type ParsingContext = Record<string, string | Record<string, string>>;
 
 export type ParsingExtension<T extends Json = Json> = (
   value: T,

app-config-default-extensions/index.js

@@ -7,12 +7,7 @@
 const { defaultAliases } = require('@app-config/node');
 
 module.exports = {
-  defaultExtensions(
-    aliases = defaultAliases,
-    environmentOverride,
-    symmetricKey,
-    environmentSourceNames,
-  ) {
+  defaultExtensions() {
     const {
       unescape$Directives,
       tryDirective,
@@ -34,13 +29,13 @@ module.exports = {
       ifDirective(),
       eqDirective(),
       hiddenDirective(),
-      envDirective(aliases, environmentOverride, environmentSourceNames),
-      envVarDirective(aliases, environmentOverride, environmentSourceNames),
+      envDirective(),
+      envVarDirective(),
       extendsDirective(),
       extendsSelfDirective(),
       overrideDirective(),
       timestampDirective(),
-      substituteDirective(aliases, environmentOverride, environmentSourceNames),
+      substituteDirective(),
     ];
   },
   defaultEnvExtensions() {

app-config-extensions/src/index.ts

@@ -14,13 +14,14 @@ import {
   FailedToSelectSubObject,
   Fallbackable,
   InObject,
+  ParsingContext,
 } from '@app-config/core';
 import {
   currentEnvironment,
-  defaultAliases,
   resolveFilepath,
-  EnvironmentAliases,
   FileSource,
+  defaultAliases,
+  EnvironmentAliases,
 } from '@app-config/node';
 import { logger } from '@app-config/logging';
 
@@ -161,19 +162,16 @@ export function extendsSelfDirective(): ParsingExtension {
 }
 
 /** Looks up an environment-specific value ($env) */
-export function envDirective(
-  aliases: EnvironmentAliases = defaultAliases,
-  environmentOverride?: string,
-  environmentSourceNames?: string[] | string,
-): ParsingExtension {
-  const environment = environmentOverride ?? currentEnvironment(aliases, environmentSourceNames);
+export function envDirective(): ParsingExtension {
   const metadata = { shouldOverride: true };
 
   return forKey(
     '$env',
     validateOptions(
       (SchemaBuilder) => SchemaBuilder.emptySchema().addAdditionalProperties(),
-      (value) => (parse) => {
+      (value, _, context) => (parse) => {
+        const environment = getEnv(context);
+
         if (!environment) {
           if ('none' in value) {
             return parse(value.none, metadata);
@@ -188,6 +186,8 @@ export function envDirective(
           );
         }
 
+        const aliases = getAliases(context);
+
         for (const [envName, envValue] of Object.entries(value)) {
           if (envName === environment || aliases[envName] === environment) {
             return parse(envValue, metadata);
@@ -248,14 +248,8 @@ export function timestampDirective(dateSource: () => Date = () => new Date()): P
 }
 
 /** Substitues environment variables */
-export function envVarDirective(
-  aliases: EnvironmentAliases = defaultAliases,
-  environmentOverride?: string,
-  environmentSourceNames?: string[] | string,
-): ParsingExtension {
-  const envType = environmentOverride ?? currentEnvironment(aliases, environmentSourceNames);
-
-  return forKey('$envVar', (value, parentKeys) => async (parse) => {
+export function envVarDirective(): ParsingExtension {
+  return forKey('$envVar', (value, parentKeys, context) => async (parse) => {
     let name: string;
     let parseInt = false;
     let parseFloat = false;
@@ -279,7 +273,7 @@ export function envVarDirective(
     let resolvedValue = process.env[name];
 
     if (!resolvedValue && name === 'APP_CONFIG_ENV') {
-      resolvedValue = envType;
+      resolvedValue = getEnv(context);
     }
 
     if (resolvedValue) {
@@ -330,16 +324,12 @@ export function envVarDirective(
 }
 
 /** Substitues environment variables found in strings (similar to bash variable substitution) */
-export function substituteDirective(
-  aliases: EnvironmentAliases = defaultAliases,
-  environmentOverride?: string,
-  environmentSourceNames?: string[] | string,
-): ParsingExtension {
-  const envType = environmentOverride ?? currentEnvironment(aliases, environmentSourceNames);
-
-  return forKey(['$substitute', '$subs'], (value, parentKeys) => async (parse) => {
+export function substituteDirective(): ParsingExtension {
+  return forKey(['$substitute', '$subs'], (value, parentKeys, context) => async (parse) => {
+    const environment = getEnv(context);
+
     if (typeof value === 'string') {
-      return parse(performAllSubstitutions(value, envType), { shouldFlatten: true });
+      return parse(performAllSubstitutions(value, environment), { shouldFlatten: true });
     }
 
     validateObject(value, parentKeys);
@@ -352,7 +342,7 @@ export function substituteDirective(
     let resolvedValue = process.env[name];
 
     if (!resolvedValue && name === 'APP_CONFIG_ENV') {
-      resolvedValue = envType;
+      resolvedValue = environment;
     }
 
     if (resolvedValue) {
@@ -533,6 +523,21 @@ function performAllSubstitutions(text: string, envType?: string): string {
   return output;
 }
 
+function getAliases(context: ParsingContext) {
+  const { environmentAliases } = context;
+
+  return (environmentAliases as EnvironmentAliases) ?? defaultAliases;
+}
+
+function getEnv(context: ParsingContext) {
+  const { environmentOverride, environmentSourceNames } = context;
+
+  return (
+    (environmentOverride as string) ??
+    currentEnvironment(getAliases(context), environmentSourceNames as string)
+  );
+}
+
 const validateObject: ValidationFunction<
   Record<string, any>
 > = validationFunction(({ emptySchema }) => emptySchema().addAdditionalProperties());

app-config-v1-compat/src/index.ts

@@ -7,9 +7,9 @@ import { logger } from '@app-config/logging';
 
 /** V1 app-config compatibility */
 export default function v1Compat(): ParsingExtension {
-  return (value, [[_, key], ...context]) => {
+  return (value, [[_, key], ...parents]) => {
     // only apply in top-level app-config property
-    if (context[context.length - 1]?.[0] !== Root) {
+    if (parents[parents.length - 1]?.[0] !== Root) {
       return false;
     }