From d12b24f6c2f6171ec9f5b5c33070366ebbe5e56d Mon Sep 17 00:00:00 2001
From: Mark Probst <mark.probst@gmail.com>
Date: Mon, 20 Jul 2026 16:36:26 -0400
Subject: [PATCH] fix(schema-input): report clean fetch error for missing
 schema paths (#2812)

When --src-lang schema was given a nonexistent source path (e.g. a literal
wildcard like '*.json' that a shell such as PowerShell doesn't expand),
JSONSchemaStore.get swallowed the fetch error and returned undefined, and
Resolver.resolveVirtualRef then tried to read virtualRef.address on a Ref
with no address, panicking with "Internal error: Defined value expected,
but got undefined." instead of a real diagnostic.

Use virtualRef.toString() (which doesn't require an address) when building
the fetch-error message, so a missing schema path now reports a normal
"Could not fetch schema ..." error instead of crashing.

Co-Authored-By: gpt-5.6-sol via pi <noreply@openai.com>
---
 .../src/input/JSONSchemaInput.ts              |  2 +-
 test/unit/missing-schema-path.test.ts         | 36 +++++++++++++++++++
 2 files changed, 37 insertions(+), 1 deletion(-)
 create mode 100644 test/unit/missing-schema-path.test.ts

diff --git a/packages/quicktype-core/src/input/JSONSchemaInput.ts b/packages/quicktype-core/src/input/JSONSchemaInput.ts
index d3a0e4feef..70a51256ee 100644
--- a/packages/quicktype-core/src/input/JSONSchemaInput.ts
+++ b/packages/quicktype-core/src/input/JSONSchemaInput.ts
@@ -783,7 +783,7 @@ class Resolver {
             return [schema, result[1]];
         }
 
-        return schemaFetchError(base, virtualRef.address);
+        return schemaFetchError(base, virtualRef.toString());
     }
 
     public async resolveTopLevelRef(ref: Ref): Promise<[JSONSchema, Location]> {
diff --git a/test/unit/missing-schema-path.test.ts b/test/unit/missing-schema-path.test.ts
new file mode 100644
index 0000000000..8656b820dd
--- /dev/null
+++ b/test/unit/missing-schema-path.test.ts
@@ -0,0 +1,36 @@
+import * as fs from "node:fs";
+import * as os from "node:os";
+import * as path from "node:path";
+
+import {
+    FetchingJSONSchemaStore,
+    InputData,
+    JSONSchemaInput,
+    quicktype,
+} from "quicktype-core";
+import { expect, test } from "vitest";
+
+// Regression test for issue #2812: shells such as PowerShell pass wildcard
+// arguments through literally, so a schema wildcard with no matching file must
+// report a normal missing-file error rather than an internal error.
+test("missing JSON Schema paths report the fetch error", async () => {
+    const tempDir = fs.mkdtempSync(
+        path.join(os.tmpdir(), "quicktype-missing-schema-"),
+    );
+    const missingPath = path.join(tempDir, "*.json");
+
+    try {
+        const schemaInput = new JSONSchemaInput(new FetchingJSONSchemaStore());
+        await schemaInput.addSource({ name: "TopLevel", uris: [missingPath] });
+        const inputData = new InputData();
+        inputData.addInput(schemaInput);
+
+        await expect(
+            quicktype({ inputData, lang: "typescript" }),
+        ).rejects.toThrow(
+            `Could not fetch schema #, referred to from ${missingPath}#`,
+        );
+    } finally {
+        fs.rmSync(tempDir, { recursive: true, force: true });
+    }
+});