From d437979c8b88870d827e708b580c2fa58d629fc9 Mon Sep 17 00:00:00 2001
From: Mark Probst <mark.probst@gmail.com>
Date: Mon, 20 Jul 2026 18:02:24 -0400
Subject: [PATCH] fix(cli): respect --src-lang schema for directory sources
 (#1278)

Co-Authored-By: gpt-5.6-sol via pi <noreply@openai.com>
---
 src/index.ts                                |  29 +++--
 test/unit/directory-source-language.test.ts | 113 ++++++++++++++++++++
 2 files changed, 134 insertions(+), 8 deletions(-)
 create mode 100644 test/unit/directory-source-language.test.ts

diff --git a/src/index.ts b/src/index.ts
index 6ae510e25b..3331df0190 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -127,6 +127,7 @@ function typeNameFromFilename(filename: string): string {
 async function samplesFromDirectory(
     dataDir: string,
     httpHeaders?: string[],
+    sourceLanguage?: string,
 ): Promise<TypeSource[]> {
     async function readFilesOrURLsInDirectory(
         d: string,
@@ -152,13 +153,21 @@ async function samplesFromDirectory(
             }
 
             if (file.endsWith(".url") || file.endsWith(".json")) {
-                sourcesInDir.push({
-                    kind: "json",
-                    name,
-                    samples: [
-                        await readableFromFileOrURL(fileOrUrl, httpHeaders),
-                    ],
-                });
+                if (sourceLanguage === "schema") {
+                    sourcesInDir.push({
+                        kind: "schema",
+                        name,
+                        uris: [fileOrUrl],
+                    });
+                } else {
+                    sourcesInDir.push({
+                        kind: "json",
+                        name,
+                        samples: [
+                            await readableFromFileOrURL(fileOrUrl, httpHeaders),
+                        ],
+                    });
+                }
             } else if (file.endsWith(".schema")) {
                 sourcesInDir.push({
                     kind: "schema",
@@ -876,7 +885,11 @@ async function getSources(options: CLIOptions): Promise<TypeSource[]> {
 
     for (const dataDir of directories) {
         sources = sources.concat(
-            await samplesFromDirectory(dataDir, options.httpHeader),
+            await samplesFromDirectory(
+                dataDir,
+                options.httpHeader,
+                options.srcLang,
+            ),
         );
     }
 
diff --git a/test/unit/directory-source-language.test.ts b/test/unit/directory-source-language.test.ts
new file mode 100644
index 0000000000..788efbe9d5
--- /dev/null
+++ b/test/unit/directory-source-language.test.ts
@@ -0,0 +1,113 @@
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
+
+import { afterEach, describe, expect, test } from "vitest";
+
+import { main } from "../../src";
+
+const temporaryDirectories: string[] = [];
+
+const personSchema = JSON.stringify({
+    $schema: "http://json-schema.org/draft-07/schema#",
+    $id: "person.schema.json",
+    title: "Person",
+    type: "object",
+    properties: {
+        name: { type: "string" },
+        age: {
+            description: "Age in years",
+            type: "integer",
+            minimum: 0,
+        },
+    },
+    required: ["name"],
+});
+
+function makeTemporaryDirectory(): string {
+    const directory = fs.mkdtempSync(
+        path.join(os.tmpdir(), "quicktype-directory-source-language-"),
+    );
+    temporaryDirectories.push(directory);
+    return directory;
+}
+
+afterEach(() => {
+    for (const directory of temporaryDirectories.splice(0)) {
+        fs.rmSync(directory, { recursive: true, force: true });
+    }
+});
+
+describe("directory source language", () => {
+    test("explicit schema source language applies to .schema.json files", async () => {
+        const temporaryDirectory = makeTemporaryDirectory();
+        const schemaDirectory = path.join(temporaryDirectory, "schemas");
+        const schemaPath = path.join(schemaDirectory, "person.schema.json");
+        const directOutputPath = path.join(
+            temporaryDirectory,
+            "direct",
+            "output.ts",
+        );
+        const directoryOutputPath = path.join(
+            temporaryDirectory,
+            "directory",
+            "output.ts",
+        );
+
+        fs.mkdirSync(schemaDirectory);
+        fs.mkdirSync(path.dirname(directOutputPath));
+        fs.mkdirSync(path.dirname(directoryOutputPath));
+        fs.writeFileSync(schemaPath, personSchema);
+
+        await main([
+            "--src-lang",
+            "schema",
+            "--lang",
+            "typescript",
+            "--out",
+            directOutputPath,
+            "--top-level",
+            "PersonSchema",
+            schemaPath,
+        ]);
+        await main([
+            "--src-lang",
+            "schema",
+            "--lang",
+            "typescript",
+            "--out",
+            directoryOutputPath,
+            "--top-level",
+            "PersonSchema",
+            schemaDirectory,
+        ]);
+
+        expect(fs.readFileSync(directoryOutputPath, "utf8")).toBe(
+            fs.readFileSync(directOutputPath, "utf8"),
+        );
+    });
+
+    test("default directory detection still recognizes .schema files", async () => {
+        const temporaryDirectory = makeTemporaryDirectory();
+        const schemaDirectory = path.join(temporaryDirectory, "schemas");
+        const schemaPath = path.join(schemaDirectory, "person.schema");
+        const outputPath = path.join(temporaryDirectory, "output.ts");
+
+        fs.mkdirSync(schemaDirectory);
+        fs.writeFileSync(schemaPath, personSchema);
+
+        await main([
+            "--lang",
+            "typescript",
+            "--out",
+            outputPath,
+            "--top-level",
+            "PersonSchema",
+            schemaDirectory,
+        ]);
+
+        const output = fs.readFileSync(outputPath, "utf8");
+        expect(output).toContain("age?: number;");
+        expect(output).not.toContain("$schema:");
+    });
+});