fix(server-runtime-injection): Keep require() of JSON working on Deno

Deno's `nextLoad` reports no module format for a `.json` file, where
Node reports `'json'`. With any load hook installed, Deno's CJS loader
then compiles the JSON as JavaScript, so `require()` of it throws
`SyntaxError: Unexpected token ':'`. A pass-through
`Module.registerHooks({ resolve, load })` reproduces this with no Sentry
code involved, on both Deno 2.8.3 and 2.9.6.

That made `@sentry/deno/import` (as a first import or as a `--preload`)
crash any app whose dependency graph requires JSON. `redis` and
`ioredis` both do, through `@ioredis/commands`.

Restoring the format in our load wrapper is enough. Node never reports a
missing format, so the wrapper only applies on Deno.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: isaacs

dev-packages/deno-integration-tests/suites/orchestrion-json-require/fixture.cjs

@@ -0,0 +1,3 @@
+// Deno reports no module format for a `.json` file, so with any load hook
+// installed its CJS loader used to compile this JSON as JavaScript.
+module.exports = require('./fixture.json');

dev-packages/deno-integration-tests/suites/orchestrion-json-require/fixture.json

@@ -0,0 +1 @@
+{ "answer": 42 }

dev-packages/deno-integration-tests/suites/orchestrion-json-require/scenario.mjs

@@ -0,0 +1,14 @@
+// Spawned by test.ts via `deno run`.
+//
+// Importing `@sentry/deno/import` registers the orchestrion module hook. No
+// module here is instrumented — the point is that installing the hook at all
+// must not change how `require()` loads JSON.
+import '@sentry/deno/import';
+
+import { createRequire } from 'node:module';
+
+const require = createRequire(import.meta.url);
+const { answer } = require('./fixture.cjs');
+
+// eslint-disable-next-line no-console
+console.log(`SCENARIO answer=${answer}`);

dev-packages/deno-integration-tests/suites/orchestrion-json-require/test.ts

@@ -0,0 +1,30 @@
+// <reference lib="deno.ns" />
+
+import { assert } from 'https://deno.land/std@0.212.0/assert/assert.ts';
+import { assertEquals } from 'https://deno.land/std@0.212.0/assert/assert_equals.ts';
+
+Deno.test('the runtime hook leaves `require()` of JSON working', async () => {
+  const scenario = new URL('./scenario.mjs', import.meta.url);
+
+  // The package root — where `node_modules` (and thus `@sentry/deno`) resolves
+  // for the spawned `deno run`.
+  const cwd = new URL('../../', import.meta.url);
+
+  const command = new Deno.Command('deno', {
+    args: ['run', '--allow-all', scenario.pathname],
+    cwd: cwd.pathname,
+    stdout: 'piped',
+    stderr: 'piped',
+  });
+
+  const { code, stdout, stderr } = await command.output();
+  const out = new TextDecoder().decode(stdout);
+  const err = new TextDecoder().decode(stderr);
+
+  // Without the format fixup in `@sentry/server-runtime-injection` this exits 1
+  // with `SyntaxError: Unexpected token ':'` from the JSON compiled as JS.
+  assertEquals(code, 0, `scenario exited ${code}\nstdout:\n${out}\nstderr:\n${err}`);
+
+  const line = out.split('\n').find(l => l.startsWith('SCENARIO')) ?? '';
+  assert(line.includes('answer=42'), `expected the parsed JSON value, got: ${line}\nstderr:\n${err}`);
+});

packages/server-runtime-injection/src/register.ts

@@ -28,6 +28,22 @@ function hasStableSyncModuleHooks(isDeno: boolean): boolean {
   return major > 25 || (major === 25 && minor >= 1) || (major === 24 && minor >= 13);
 }
 
+/**
+ * Deno's `nextLoad` reports no `format` for a `.json` file, where Node reports `'json'`. With any
+ * load hook installed, Deno's CJS loader then compiles the JSON as JavaScript and `require()` of it
+ * throws `SyntaxError: Unexpected token ':'`. Restoring the format is enough, and only Deno needs
+ * it: on Node the format is never missing.
+ */
+function withDenoJsonFormat(loadHook: Function): Function {
+  return (url: string, context: unknown, nextLoad: Function) => {
+    const result = loadHook(url, context, nextLoad) as { format?: string };
+    if (result?.format === undefined && url.endsWith('.json')) {
+      result.format = 'json';
+    }
+    return result;
+  };
+}
+
 /**
  * Emit an always-on warning. Unlike `debug.warn` (gated behind `debug: true`), this reaches every
  * user — otherwise a broken transform silently records no channel-based spans.
@@ -165,7 +181,7 @@ export function registerDiagnosticsChannelInjection(): void {
   try {
     if (typeof mod.registerHooks === 'function' && stableSyncHooks) {
       initialize({ instrumentations: SENTRY_RUNTIME_INSTRUMENTATIONS });
-      mod.registerHooks({ resolve, load });
+      mod.registerHooks({ resolve, load: globalAny.Deno ? withDenoJsonFormat(load) : load });
       debug.log('Registered diagnostics-channel injection via Module.registerHooks()');
     } else if (typeof mod.register === 'function' && !globalAny.Bun && !globalAny.Deno) {
       // `Module.register` + the `_compile` patch is Node 18.19–24.12 / 25.0