1 files changed, 43 insertions, 0 deletions
diff --git a/runtime/js/40_read_file.js b/runtime/js/40_read_file.js
new file mode 100644
index 000000000..9a36f335b
--- /dev/null
+++ b/runtime/js/40_read_file.js
@@ -0,0 +1,43 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+((window) => {
+  const { open, openSync } = window.__bootstrap.files;
+  const { readAll, readAllSync } = window.__bootstrap.buffer;
+
+  function readFileSync(path) {
+    const file = openSync(path);
+    const contents = readAllSync(file);
+    file.close();
+    return contents;
+  }
+
+  async function readFile(path) {
+    const file = await open(path);
+    const contents = await readAll(file);
+    file.close();
+    return contents;
+  }
+
+  function readTextFileSync(path) {
+    const file = openSync(path);
+    const contents = readAllSync(file);
+    file.close();
+    const decoder = new TextDecoder();
+    return decoder.decode(contents);
+  }
+
+  async function readTextFile(path) {
+    const file = await open(path);
+    const contents = await readAll(file);
+    file.close();
+    const decoder = new TextDecoder();
+    return decoder.decode(contents);
+  }
+
+  window.__bootstrap.readFile = {
+    readFile,
+    readFileSync,
+    readTextFileSync,
+    readTextFile,
+  };
+})(this);