feat: adds validateOptions utility in extension-utils

Author: joelgallant

app-config-extension-utils/package.json

@@ -30,7 +30,8 @@
     "prepublishOnly": "yarn clean && yarn build && yarn build:es"
   },
   "dependencies": {
-    "@app-config/core": "^2.1.5"
+    "@app-config/core": "^2.1.5",
+    "@serafin/schema-builder": "0.14"
   },
   "devDependencies": {},
   "prettier": "@lcdev/prettier",

app-config-extension-utils/src/index.test.ts

@@ -1,5 +1,10 @@
 import { LiteralSource } from '@app-config/core';
-import { forKey, composeExtensions } from './index';
+import {
+  forKey,
+  composeExtensions,
+  validateOptions,
+  ParsingExtensionInvalidOptions,
+} from './index';
 
 const foo = forKey('$foo', () => (parse) => parse('foo!'));
 const bar = forKey('$bar', () => (parse) => parse('bar!'));
@@ -86,3 +91,48 @@ describe('composeExtensions', () => {
     });
   });
 });
+
+describe('validateOptions', () => {
+  const ext1 = validateOptions(
+    (SchemaBuilder) => SchemaBuilder.stringSchema(),
+    (value) => (parse) => parse(value + '!', { shouldFlatten: true }),
+  );
+
+  const ext2 = validateOptions(
+    (SchemaBuilder) => SchemaBuilder.integerSchema(),
+    (value) => (parse) => parse(value + 42, { shouldFlatten: true }),
+  );
+
+  const ext3 = forKey(
+    '$ext3',
+    validateOptions(
+      (SchemaBuilder) => SchemaBuilder.integerSchema(),
+      (value) => (parse) => parse(value + 42, { shouldFlatten: true }),
+    ),
+  );
+
+  it('allows valid options', async () => {
+    expect(await new LiteralSource('start').readToJSON([ext1])).toEqual('start!');
+    expect(await new LiteralSource(42).readToJSON([ext2])).toEqual(84);
+  });
+
+  it('disallows invalid options', async () => {
+    await expect(new LiteralSource(42).readToJSON([ext1])).rejects.toThrow(
+      ParsingExtensionInvalidOptions,
+    );
+    await expect(new LiteralSource('start').readToJSON([ext2])).rejects.toThrow(
+      ParsingExtensionInvalidOptions,
+    );
+  });
+
+  it('composes forKey and validateOptions', async () => {
+    expect(await new LiteralSource('start').readToJSON([ext3])).toEqual('start');
+    expect(await new LiteralSource({ $ext3: 0 }).readToJSON([ext3])).toEqual(42);
+    await expect(new LiteralSource({ $ext3: 'start' }).readToJSON([ext3])).rejects.toThrow(
+      'Validation failed in "$ext3": Invalid parameters: data should be integer',
+    );
+    await expect(new LiteralSource({ a: { $ext3: 'start' } }).readToJSON([ext3])).rejects.toThrow(
+      'Validation failed in "a.$ext3": Invalid parameters: data should be integer',
+    );
+  });
+});

app-config-extension-utils/src/index.ts

@@ -1,5 +1,18 @@
-import type { ParsingExtension, ParsingExtensionKey } from '@app-config/core';
-import { parseValue, Root } from '@app-config/core';
+import type {
+  ParsingExtension,
+  ParsingExtensionKey,
+  ParsingExtensionTransform,
+} from '@app-config/core';
+import { parseValue, Root, AppConfigError } from '@app-config/core';
+import { SchemaBuilder } from '@serafin/schema-builder';
+
+export function composeExtensions(extensions: ParsingExtension[]): ParsingExtension {
+  return (value, [k]) => {
+    if (k !== Root) return false;
+
+    return (_, __, source) => parseValue(value, source, extensions, { shouldFlatten: true });
+  };
+}
 
 export function forKey(
   key: string | string[],
@@ -24,10 +37,37 @@ export function forKey(
   };
 }
 
-export function composeExtensions(extensions: ParsingExtension[]): ParsingExtension {
-  return (value, [k]) => {
-    if (k !== Root) return false;
+export class ParsingExtensionInvalidOptions extends AppConfigError {}
 
-    return (_, __, source) => parseValue(value, source, extensions, { shouldFlatten: true });
+export function validateOptions<T>(
+  builder: (builder: typeof SchemaBuilder) => SchemaBuilder<T>,
+  extension: (
+    value: T,
+    key: ParsingExtensionKey,
+    context: ParsingExtensionKey[],
+  ) => ParsingExtensionTransform | false,
+): ParsingExtension {
+  const schema = builder(SchemaBuilder);
+
+  schema.cacheValidationFunction();
+
+  return (value, ctxKey, ctx) => {
+    const valid = (value as unknown) as T;
+
+    try {
+      schema.validate(valid);
+    } catch (error) {
+      const message = error instanceof Error ? error.message : 'unknown';
+
+      const parents =
+        [...ctx, ctxKey]
+          .map(([, k]) => k)
+          .filter((v) => !!v)
+          .join('.') || 'root';
+
+      throw new ParsingExtensionInvalidOptions(`Validation failed in "${parents}": ${message}`);
+    }
+
+    return extension(valid, ctxKey, ctx);
   };
 }

yarn.lock

@@ -2712,6 +2712,14 @@
   dependencies:
     any-observable "^0.3.0"
 
+"@serafin/[email protected]":
+  version "0.14.2"
+  resolved "https://registry.yarnpkg.com/@serafin/schema-builder/-/schema-builder-0.14.2.tgz#38d3c712e8642787a4e87e272b0a60ca5b1f671c"
+  integrity sha512-JvGTNp5P4BNxB+olM4E89E1W7/GXAi4JRpaxKnN4S6C/YpMq5RIJzaJUYEmSaCWWpmANK9juEx2x1DgVueE5Uw==
+  dependencies:
+    ajv "^6.12.4"
+    verror "^1.10.0"
+
 "@sindresorhus/is@^0.14.0":
   version "0.14.0"
   resolved "https://registry.yarnpkg.com/@sindresorhus/is/-/is-0.14.0.tgz#9fb3a3cf3132328151f353de4632e01e52102bea"
@@ -17165,7 +17173,7 @@ vendors@^1.0.0:
   resolved "https://registry.yarnpkg.com/vendors/-/vendors-1.0.4.tgz#e2b800a53e7a29b93506c3cf41100d16c4c4ad8e"
   integrity sha512-/juG65kTL4Cy2su4P8HjtkTxk6VmJDiOPBufWniqQ6wknac6jNiXS9vU+hO3wgusiyqWlzTbVHi0dyJqRONg3w==
 
-[email protected]:
+[email protected], verror@^1.10.0:
   version "1.10.0"
   resolved "https://registry.yarnpkg.com/verror/-/verror-1.10.0.tgz#3a105ca17053af55d6e270c1f8288682e18da400"
   integrity sha1-OhBcoXBTr1XW4nDB+CiGguGNpAA=