1 files changed, 33 insertions, 0 deletions
diff --git a/src/utils/base64.ts b/src/utils/base64.ts
new file mode 100644
index 0000000..c0ef96a
--- /dev/null
+++ b/src/utils/base64.ts
@@ -0,0 +1,33 @@
+export { textToBase64, base64ToText, isValidBase64, removePotentialDataAndMimePrefix };
+
+function textToBase64(str: string) {
+  return window.btoa(str);
+}
+
+function base64ToText(str: string) {
+  if (!isValidBase64(str)) {
+    throw new Error('Incorrect base64 string');
+  }
+
+  const cleanStr = removePotentialDataAndMimePrefix(str);
+
+  try {
+    return window.atob(cleanStr);
+  } catch (_) {
+    throw new Error('Incorrect base64 string');
+  }
+}
+
+function removePotentialDataAndMimePrefix(str: string) {
+  return str.replace(/^data:.*?;base64,/, '');
+}
+
+function isValidBase64(str: string) {
+  const cleanStr = removePotentialDataAndMimePrefix(str);
+
+  try {
+    return window.btoa(window.atob(cleanStr)) === cleanStr;
+  } catch (err) {
+    return false;
+  }
+}