Use more strict type for schema (#134)

* Use more strict type for schema

* Add type support for third-party json-schema libraries

README.md

@@ -154,7 +154,7 @@ const config = envSchema({
   schema: schema,
   data: data, // optional, default: process.env
   dotenv: true // load .env if it is there, default: false
-}) 
+})
 
 // config.data => ['127.0.0.1', '0.0.0.0']
 ```
@@ -198,13 +198,13 @@ console.log(config)
 You can specify the type of your `config`:
 
 ```ts
-import envSchema from 'env-schema';
+import { envSchema, JSONSchemaType } from 'env-schema'
 
 interface Env {
   PORT: number;
 }
 
-const schema = {
+const schema: JSONSchemaType<Env> = {
   type: 'object',
   required: [ 'PORT' ],
   properties: {
@@ -215,8 +215,25 @@ const schema = {
   }
 }
 
-const config = envSchema<Env>({
-  schema,
+const config = envSchema({
+  schema
+})
+```
+
+You can also use a `JSON Schema` library like `typebox`:
+
+```ts
+import { envSchema } from 'env-schema'
+import { Static, Type } from '@sinclair/typebox'
+
+const schema = Type.Object({
+  PORT: Type.Number({ default: 3000 })
+})
+
+type Schema = Static<typeof schema>
+
+const config = envSchema<Schema>({
+  schema
 })
 ```
 

package.json

@@ -36,6 +36,7 @@
   },
   "devDependencies": {
     "@fastify/pre-commit": "^2.0.2",
+    "@sinclair/typebox": "^0.24.43",
     "ajv-formats": "^2.1.1",
     "fluent-json-schema": "^3.0.0",
     "snazzy": "^9.0.0",

types/index.d.ts

@@ -1,27 +1,33 @@
-import Ajv, { KeywordDefinition } from "ajv";
-import { DotenvConfigOptions } from "dotenv";
+import Ajv, { KeywordDefinition, JSONSchemaType } from 'ajv';
+import { AnySchema } from 'ajv/dist/core';
+import { DotenvConfigOptions } from 'dotenv';
+import { ObjectSchema } from 'fluent-json-schema';
+
+export type { JSONSchemaType };
 
 export type EnvSchemaData = {
   [key: string]: unknown;
 };
 
-export type EnvSchemaOpt = {
-  schema?: object;
+export type EnvSchemaOpt<T = EnvSchemaData> = {
+  schema?: JSONSchemaType<T> | AnySchema | ObjectSchema;
   data?: [EnvSchemaData, ...EnvSchemaData[]] | EnvSchemaData;
   env?: boolean;
   dotenv?: boolean | DotenvConfigOptions;
-  expandEnv?: boolean
-  ajv?: Ajv | {
-    customOptions(ajvInstance: Ajv): Ajv;
-  };
+  expandEnv?: boolean;
+  ajv?:
+    | Ajv
+    | {
+        customOptions(ajvInstance: Ajv): Ajv;
+      };
 };
 
 declare const loadAndValidateEnvironment: {
-  <T = EnvSchemaData>(_opts?: EnvSchemaOpt): T;
+  <T = EnvSchemaData>(_opts?: EnvSchemaOpt<T>): T;
   keywords: {
     separator: KeywordDefinition;
-  }
-}
+  };
+};
 
 export default loadAndValidateEnvironment;
 export { loadAndValidateEnvironment as envSchema };

types/index.test-d.ts

@@ -1,19 +1,36 @@
-import { expectError, expectType } from "tsd";
-import envSchema, { EnvSchemaData, EnvSchemaOpt, envSchema as envSchemaNamed, default as envSchemaDefault } from "..";
-import Ajv, { KeywordDefinition } from 'ajv'
+import { expectError, expectType } from 'tsd';
+import envSchema, {
+  EnvSchemaData,
+  EnvSchemaOpt,
+  envSchema as envSchemaNamed,
+  default as envSchemaDefault,
+} from '..';
+import Ajv, { KeywordDefinition, JSONSchemaType } from 'ajv';
+import { Static, Type } from '@sinclair/typebox';
 
-const schema = {
-  type: "object",
-  required: ["PORT"],
+interface EnvData {
+  PORT: number;
+}
+
+const schemaWithType: JSONSchemaType<EnvData> = {
+  type: 'object',
+  required: ['PORT'],
   properties: {
     PORT: {
-      type: "string",
+      type: 'number',
       default: 3000,
     },
   },
 };
+
+const schemaTypebox = Type.Object({
+  PORT: Type.Number({ default: 3000 }),
+});
+
+type SchemaTypebox = Static<typeof schemaTypebox>;
+
 const data = {
-  foo: "bar",
+  foo: 'bar',
 };
 
 expectType<EnvSchemaData>(envSchema());
@@ -23,10 +40,15 @@ expectType<EnvSchemaData>(envSchemaDefault());
 const emptyOpt: EnvSchemaOpt = {};
 expectType<EnvSchemaOpt>(emptyOpt);
 
-const optWithSchema: EnvSchemaOpt = {
-  schema,
+const optWithSchemaTypebox: EnvSchemaOpt = {
+  schema: schemaTypebox,
+};
+expectType<EnvSchemaOpt>(optWithSchemaTypebox);
+
+const optWithSchemaWithType: EnvSchemaOpt<EnvData> = {
+  schema: schemaWithType,
 };
-expectType<EnvSchemaOpt>(optWithSchema);
+expectType<EnvSchemaOpt<EnvData>>(optWithSchemaWithType);
 
 const optWithData: EnvSchemaOpt = {
   data,
@@ -58,37 +80,32 @@ const optWithDotEnvOpt: EnvSchemaOpt = {
 expectType<EnvSchemaOpt>(optWithDotEnvOpt);
 
 const optWithEnvExpand: EnvSchemaOpt = {
-  expandEnv: true
-}
+  expandEnv: true,
+};
 expectType<EnvSchemaOpt>(optWithEnvExpand);
 
 const optWithAjvInstance: EnvSchemaOpt = {
-  ajv: new Ajv()
+  ajv: new Ajv(),
 };
-expectType<EnvSchemaOpt>(optWithAjvInstance)
-expectType<KeywordDefinition>(envSchema.keywords.separator)
-
+expectType<EnvSchemaOpt>(optWithAjvInstance);
+expectType<KeywordDefinition>(envSchema.keywords.separator);
 
 const optWithAjvCustomOptions: EnvSchemaOpt = {
-    ajv: {
-        customOptions(ajvInstance: Ajv): Ajv {
-            return new Ajv();
-        }
-    }
+  ajv: {
+    customOptions(ajvInstance: Ajv): Ajv {
+      return new Ajv();
+    },
+  },
 };
-expectType<EnvSchemaOpt>(optWithAjvCustomOptions)
+expectType<EnvSchemaOpt>(optWithAjvCustomOptions);
 expectError<EnvSchemaOpt>({
-    ajv: {
-        customOptions(ajvInstance: Ajv) {
-        }
-    }
+  ajv: {
+    customOptions(ajvInstance: Ajv) {},
+  },
 });
 
-const envSchemaDefaultsToEnvSchemaData = envSchema({ schema: schema });
-expectType<EnvSchemaData>(envSchemaDefaultsToEnvSchemaData)
+const envSchemaWithType = envSchema({ schema: schemaWithType });
+expectType<EnvData>(envSchemaWithType);
 
-interface EnvData {
-  PORT: string
-}
-const envSchemaAllowsToSpecifyType = envSchema<EnvData>({ schema });
-expectType<EnvData>(envSchemaAllowsToSpecifyType)
+const envSchemaTypebox = envSchema<SchemaTypebox>({ schema: schemaTypebox });
+expectType<SchemaTypebox>(envSchemaTypebox);