feat: Generate inferred types (#85)

* Fix github flow

* Add `inferredTypes` option

* Add inferredTypes in the example

* Fix doc

.github/workflows/tests.yaml

@@ -3,18 +3,18 @@ name: Tests
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
-    types: [ opened, synchronize, reopened ]
-    
+    types: [opened, synchronize, reopened]
+
 jobs:
   test:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1
         with:
-          node-version: 12.16.1
+          node-version: 16.13.1
       - run: yarn
       - run: chmod +x ./bin/run
       - run: yarn test:ci

example/heros.types.ts

@@ -0,0 +1,36 @@
+// Generated by ts-to-zod
+import { z } from "zod";
+
+import * as generated from "./heros.zod";
+
+export type EnemyPower = z.infer<typeof generated.enemyPowerSchema>;
+
+export type SkillsSpeedEnemy = z.infer<typeof generated.skillsSpeedEnemySchema>;
+
+export type Enemy = z.infer<typeof generated.enemySchema>;
+
+export type Superman = z.infer<typeof generated.supermanSchema>;
+
+export type Villain = z.infer<typeof generated.villainSchema>;
+
+export type Story = z.infer<typeof generated.storySchema>;
+
+export type KrytonResponse = z.infer<typeof generated.krytonResponseSchema>;
+
+export type KillSuperman = z.infer<typeof generated.killSupermanSchema>;
+
+export type WithDefaults = z.infer<typeof generated.withDefaultsSchema>;
+
+export type Exported = z.infer<typeof generated.exportedSchema>;
+
+export type GetSupermanSkill = z.infer<typeof generated.getSupermanSkillSchema>;
+
+export type HeroContact = z.infer<typeof generated.heroContactSchema>;
+
+export type SupermanEnemy = z.infer<typeof generated.supermanEnemySchema>;
+
+export type SupermanName = z.infer<typeof generated.supermanNameSchema>;
+
+export type SupermanInvinciblePower = z.infer<
+  typeof generated.supermanInvinciblePowerSchema
+>;

src/cli.ts

@@ -83,6 +83,9 @@ class TsToZod extends Command {
       default: false,
       description: "Skip the validation step (not recommended)",
     }),
+    inferredTypes: flags.string({
+      description: "Path of z.infer<> types file",
+    }),
     watch: flags.boolean({
       char: "w",
       default: false,
@@ -239,12 +242,16 @@ See more help with --help`,
     if (typeof flags.skipParseJSDoc === "boolean") {
       generateOptions.skipParseJSDoc = flags.skipParseJSDoc;
     }
+    if (typeof flags.inferredTypes === "string") {
+      generateOptions.inferredTypes = flags.inferredTypes;
+    }
 
     const {
       errors,
       transformedSourceText,
       getZodSchemasFile,
       getIntegrationTestFile,
+      getInferredTypes,
       hasCircularDependencies,
     } = generate(generateOptions);
 
@@ -295,6 +302,27 @@ See more help with --help`,
 
     const prettierConfig = await prettier.resolveConfig(process.cwd());
 
+    if (generateOptions.inferredTypes) {
+      const zodInferredTypesFile = getInferredTypes(
+        getImportPath(generateOptions.inferredTypes, outputPath)
+      );
+      await outputFile(
+        generateOptions.inferredTypes,
+        prettier.format(
+          hasExtensions(generateOptions.inferredTypes, javascriptExtensions)
+            ? ts.transpileModule(zodInferredTypesFile, {
+                compilerOptions: {
+                  target: ts.ScriptTarget.Latest,
+                  module: ts.ModuleKind.ESNext,
+                  newLine: ts.NewLineKind.LineFeed,
+                },
+              }).outputText
+            : zodInferredTypesFile,
+          { parser: "babel-ts", ...prettierConfig }
+        )
+      );
+    }
+
     if (output && hasExtensions(output, javascriptExtensions)) {
       await outputFile(
         outputPath,

src/config.ts

@@ -61,6 +61,11 @@ export type Config = {
    * @default false
    */
   skipParseJSDoc?: boolean;
+
+  /**
+   * Path of z.infer<> types file.
+   */
+  inferredTypes?: string;
 };
 
 export type Configs = Array<

src/config.zod.ts

@@ -30,6 +30,7 @@ export const configSchema = z.object({
   getSchemaName: getSchemaNameSchema.optional(),
   keepComments: z.boolean().optional().default(false),
   skipParseJSDoc: z.boolean().optional().default(false),
+  inferredTypes: z.string().optional(),
 });
 
 export const configsSchema = z.array(

src/core/generate.ts

@@ -47,6 +47,11 @@ export interface GenerateProps {
    * @default false
    */
   skipParseJSDoc?: boolean;
+
+  /**
+   * Path of z.infer<> types file.
+   */
+  inferredTypes?: string;
 }
 
 /**
@@ -283,6 +288,27 @@ ${Array.from(statements.values())
 ${testCases.map(print).join("\n")}
 `;
 
+  const getInferredTypes = (
+    zodSchemasImportPath: string
+  ) => `// Generated by ts-to-zod
+import { z } from "zod";
+
+import * as generated from "${zodSchemasImportPath}";
+
+${Array.from(statements.values())
+  .filter(isExported)
+  .map((statement) => {
+    const zodInferredSchema = generateZodInferredType({
+      aliasName: statement.typeName,
+      zodConstName: `generated.${getSchemaName(statement.typeName)}`,
+      zodImportValue: "z",
+    });
+
+    return print(zodInferredSchema);
+  })
+  .join("\n\n")}
+`;
+
   return {
     /**
      * Source text with pre-process applied.
@@ -304,6 +330,13 @@ ${testCases.map(print).join("\n")}
      */
     getIntegrationTestFile,
 
+    /**
+     * Get the content of the zod inferred types files.
+     *
+     * @param zodSchemasImportPath Relative path of the zod schemas file
+     */
+    getInferredTypes,
+
     /**
      * List of generation errors.
      */

ts-to-zod.config.js

@@ -8,6 +8,7 @@ module.exports = [
     name: "example",
     input: "example/heros.ts",
     output: "example/heros.zod.ts",
+    inferredTypes: "example/heros.types.ts",
   },
   { name: "config", input: "src/config.ts", output: "src/config.zod.ts" },
 ];