diff --git a/test/prebuild/environment.test.js b/test/prebuild/environment.test.js
new file mode 100644
index 0000000..e3be839
--- /dev/null
+++ b/test/prebuild/environment.test.js
@@ -0,0 +1,24 @@
+import { describe, expect, it } from 'vitest'
+
+import {
+    isBrowserContext,
+    isDarwin,
+    isLinux
+} from '~/helpers/environment.js'
+
+describe( 'environment helpers', () => {
+    it( 'does not treat Node 22 navigator as a browser runtime', () => {
+        expect( isBrowserContext() ).toBe( false )
+    })
+
+    it( 'detects darwin directly from process.platform', () => {
+        expect( isDarwin() ).toBe( process.platform === 'darwin' )
+    })
+
+    it( 'detects linux-like runtimes directly from process.platform', () => {
+        expect( isLinux() ).toBe([
+            'linux',
+            'openbsd'
+        ].includes( process.platform ) )
+    })
+})
diff --git a/test/prebuild/stork-executable.test.js b/test/prebuild/stork-executable.test.js
new file mode 100644
index 0000000..3a44c1e
--- /dev/null
+++ b/test/prebuild/stork-executable.test.js
@@ -0,0 +1,29 @@
+import { describe, expect, it } from 'vitest'
+
+import {
+    getStorkExecutableTarget,
+    getStorkExecutableDownloadUrl
+} from '~/helpers/stork/executable.js'
+
+describe( 'stork executable selection', () => {
+    it( 'uses the Ubuntu 22.04 binary for Linux builds', () => {
+        expect( getStorkExecutableTarget({
+            platform: 'linux',
+            arch: 'x64'
+        }) ).toBe( 'stork-ubuntu-22-04' )
+    })
+
+    it( 'uses the Apple Silicon macOS binary on arm64 Macs', () => {
+        expect( getStorkExecutableTarget({
+            platform: 'darwin',
+            arch: 'arm64'
+        }) ).toBe( 'stork-macos-13-arm' )
+    })
+
+    it( 'builds the download URL from the selected target', () => {
+        expect( getStorkExecutableDownloadUrl({
+            platform: 'linux',
+            arch: 'x64'
+        }) ).toContain( '/stork-ubuntu-22-04' )
+    })
+})