refactor(core): Centralize shell logic into ShellExecutionService (#4823)

1 files changed, 34 insertions, 0 deletions

diff --git a/packages/core/src/utils/textUtils.ts b/packages/core/src/utils/textUtils.ts
new file mode 100644
index 00000000..3bcc4759
--- /dev/null
+++ b/packages/core/src/utils/textUtils.ts
@@ -0,0 +1,34 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Checks if a Buffer is likely binary by testing for the presence of a NULL byte.
+ * The presence of a NULL byte is a strong indicator that the data is not plain text.
+ * @param data The Buffer to check.
+ * @param sampleSize The number of bytes from the start of the buffer to test.
+ * @returns True if a NULL byte is found, false otherwise.
+ */
+export function isBinary(
+  data: Buffer | null | undefined,
+  sampleSize = 512,
+): boolean {
+  if (!data) {
+    return false;
+  }
+
+  const sample = data.length > sampleSize ? data.subarray(0, sampleSize) : data;
+
+  for (const byte of sample) {
+    // The presence of a NULL byte (0x00) is one of the most reliable
+    // indicators of a binary file. Text files should not contain them.
+    if (byte === 0) {
+      return true;
+    }
+  }
+
+  // If no NULL bytes were found in the sample, we assume it's text.
+  return false;
+}