From f0886be90b21b5014e83a9651cccad111b0b77fb Mon Sep 17 00:00:00 2001
From: Pawel Kosiec <pawel.kosiec@databricks.com>
Date: Tue, 17 Mar 2026 20:13:46 +0100
Subject: [PATCH] chore: generate appKitTypes.d.ts during template
 post-processing

When DATABRICKS_WAREHOUSE_ID is not set, `appkit generate-types` exits
early without writing the file. This leaves templates with analytics
queries missing appKitTypes.d.ts entirely, causing TS build errors.

Add a fixAppKitTypes() post-processing step that either patches
`result: unknown` in an existing file, or generates the file from
scratch by scanning SQL files and using known result types.

Co-authored-by: Isaac
---
 tools/generate-app-templates.ts | 95 ++++++++++++++++++++++++++++++++-
 1 file changed, 94 insertions(+), 1 deletion(-)

diff --git a/tools/generate-app-templates.ts b/tools/generate-app-templates.ts
index d429ea59..1e16619f 100644
--- a/tools/generate-app-templates.ts
+++ b/tools/generate-app-templates.ts
@@ -20,11 +20,12 @@ import { spawnSync } from "node:child_process";
 import {
   existsSync,
   mkdirSync,
+  readdirSync,
   readFileSync,
   rmSync,
   writeFileSync,
 } from "node:fs";
-import { join, resolve } from "node:path";
+import { basename, join, resolve } from "node:path";
 
 const ROOT = resolve(import.meta.dirname, "..");
 
@@ -39,6 +40,17 @@ const DATABRICKS_CLI = process.env.DATABRICKS_CLI ?? "databricks";
 const APPKIT_SECTION_START = "<!-- appkit-start -->";
 const APPKIT_SECTION_END = "<!-- appkit-end -->";
 
+/**
+ * Known query result types for template SQL files.
+ * The type generator cannot infer these without a warehouse connection,
+ * so we hardcode them here to fix up `result: unknown` in appKitTypes.d.ts.
+ */
+const QUERY_RESULT_TYPES: Record<string, string> = {
+  hello_world: "Array<{ value: string }>",
+  mocked_sales:
+    "Array<{ month: string; month_num: number; revenue: number; expenses: number; customers: number }>",
+};
+
 interface AppTemplate {
   /** Output directory name and --name passed to databricks apps init */
   name: string;
@@ -191,6 +203,87 @@ function postProcess(appDir: string, app: AppTemplate): void {
     "host: https://your-workspace.cloud.databricks.com",
   );
   writeFileSync(databricksYmlPath, fixedYml);
+
+  // 4. Fix `result: unknown` in appKitTypes.d.ts — the type generator falls back
+  //    to `unknown` when no warehouse is available during template generation.
+  fixAppKitTypes(appDir);
+}
+
+/**
+ * Ensures appKitTypes.d.ts has correct result types. When no warehouse is
+ * available, the type generator either exits early (file missing) or falls
+ * back to `result: unknown`. This function handles both cases.
+ */
+function fixAppKitTypes(appDir: string): void {
+  const typesPath = join(appDir, "client/src/appKitTypes.d.ts");
+  const queriesDir = join(appDir, "config/queries");
+
+  if (!existsSync(queriesDir)) return;
+
+  if (existsSync(typesPath)) {
+    // Patch existing file: replace `result: unknown` with known types
+    let content = readFileSync(typesPath, "utf-8");
+    let replaced = false;
+
+    for (const [queryName, resultType] of Object.entries(QUERY_RESULT_TYPES)) {
+      const pattern = new RegExp(
+        `(${queryName}:\\s*\\{[\\s\\S]*?)result:\\s*unknown;`,
+      );
+      if (pattern.test(content)) {
+        content = content.replace(pattern, `$1result: ${resultType};`);
+        replaced = true;
+      }
+    }
+
+    if (replaced) {
+      writeFileSync(typesPath, content);
+      console.log(`  Fixed appKitTypes.d.ts result types`);
+    }
+  } else {
+    // File missing (no warehouse ID → type generator exited early).
+    // Generate it from scratch by scanning SQL files.
+    const sqlFiles = readdirSync(queriesDir).filter((f) => f.endsWith(".sql"));
+    if (sqlFiles.length === 0) return;
+
+    const queryEntries = sqlFiles.map((file) => {
+      const queryName = basename(file, ".sql");
+      const sql = readFileSync(join(queriesDir, file), "utf-8");
+
+      // Extract :paramName placeholders (same regex as the real type generator)
+      const params = [
+        ...new Set([...sql.matchAll(/:([a-zA-Z_]\w*)/g)].map((m) => m[1])),
+      ];
+
+      const paramLines = params
+        .map(
+          (p) =>
+            `          /** any - use sql.*() */\n          ${p}: SQLTypeMarker;`,
+        )
+        .join("\n");
+      const paramSection = params.length
+        ? `{\n${paramLines}\n        }`
+        : "Record<string, never>";
+
+      const resultType = QUERY_RESULT_TYPES[queryName] ?? "unknown";
+
+      return `    ${queryName}: {\n        name: "${queryName}";\n        parameters: ${paramSection};\n        result: ${resultType};\n      }`;
+    });
+
+    const content = `// Auto-generated by AppKit - DO NOT EDIT
+// Generated by 'npx @databricks/appkit generate-types' or Vite plugin during build
+import "@databricks/appkit-ui/react";
+import type { SQLTypeMarker, SQLStringMarker, SQLNumberMarker, SQLBooleanMarker, SQLBinaryMarker, SQLDateMarker, SQLTimestampMarker } from "@databricks/appkit-ui/js";
+
+declare module "@databricks/appkit-ui/react" {
+  interface QueryRegistry {
+${queryEntries.join(";\n")};\n  }
+}
+`;
+
+    mkdirSync(join(appDir, "client/src"), { recursive: true });
+    writeFileSync(typesPath, content);
+    console.log(`  Generated appKitTypes.d.ts with ${sqlFiles.length} queries`);
+  }
 }
 
 /**