Clarify writeFile options and avoid unexpected perm modification (#1643)

1 files changed, 118 insertions, 2 deletions

diff --git a/js/write_file_test.ts b/js/write_file_test.ts
index e9e620363..7a43dec62 100644
--- a/js/write_file_test.ts
+++ b/js/write_file_test.ts
@@ -6,7 +6,7 @@ testPerm({ write: true }, function writeFileSyncSuccess() {
   const enc = new TextEncoder();
   const data = enc.encode("Hello");
   const filename = deno.makeTempDirSync() + "/test.txt";
-  deno.writeFileSync(filename, data, 0o666);
+  deno.writeFileSync(filename, data);
   const dataRead = deno.readFileSync(filename);
   const dec = new TextDecoder("utf-8");
   const actual = dec.decode(dataRead);
@@ -45,11 +45,69 @@ testPerm({ write: false }, function writeFileSyncPerm() {
   assert(caughtError);
 });
 
+testPerm({ write: true }, function writeFileSyncUpdatePerm() {
+  if (deno.platform.os !== "win") {
+    const enc = new TextEncoder();
+    const data = enc.encode("Hello");
+    const filename = deno.makeTempDirSync() + "/test.txt";
+    deno.writeFileSync(filename, data, { perm: 0o755 });
+    assertEqual(deno.statSync(filename).mode & 0o777, 0o755);
+    deno.writeFileSync(filename, data, { perm: 0o666 });
+    assertEqual(deno.statSync(filename).mode & 0o777, 0o666);
+  }
+});
+
+testPerm({ write: true }, function writeFileSyncCreate() {
+  const enc = new TextEncoder();
+  const data = enc.encode("Hello");
+  const filename = deno.makeTempDirSync() + "/test.txt";
+  let caughtError = false;
+  // if create turned off, the file won't be created
+  try {
+    deno.writeFileSync(filename, data, { create: false });
+  } catch (e) {
+    caughtError = true;
+    assertEqual(e.kind, deno.ErrorKind.NotFound);
+    assertEqual(e.name, "NotFound");
+  }
+  assert(caughtError);
+
+  // Turn on create, should have no error
+  deno.writeFileSync(filename, data, { create: true });
+  deno.writeFileSync(filename, data, { create: false });
+  const dataRead = deno.readFileSync(filename);
+  const dec = new TextDecoder("utf-8");
+  const actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
+});
+
+testPerm({ write: true }, function writeFileSyncAppend() {
+  const enc = new TextEncoder();
+  const data = enc.encode("Hello");
+  const filename = deno.makeTempDirSync() + "/test.txt";
+  deno.writeFileSync(filename, data);
+  deno.writeFileSync(filename, data, { append: true });
+  let dataRead = deno.readFileSync(filename);
+  const dec = new TextDecoder("utf-8");
+  let actual = dec.decode(dataRead);
+  assertEqual("HelloHello", actual);
+  // Now attempt overwrite
+  deno.writeFileSync(filename, data, { append: false });
+  dataRead = deno.readFileSync(filename);
+  actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
+  // append not set should also overwrite
+  deno.writeFileSync(filename, data);
+  dataRead = deno.readFileSync(filename);
+  actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
+});
+
 testPerm({ write: true }, async function writeFileSuccess() {
   const enc = new TextEncoder();
   const data = enc.encode("Hello");
   const filename = deno.makeTempDirSync() + "/test.txt";
-  await deno.writeFile(filename, data, 0o666);
+  await deno.writeFile(filename, data);
   const dataRead = deno.readFileSync(filename);
   const dec = new TextDecoder("utf-8");
   const actual = dec.decode(dataRead);
@@ -87,3 +145,61 @@ testPerm({ write: false }, async function writeFilePerm() {
   }
   assert(caughtError);
 });
+
+testPerm({ write: true }, async function writeFileUpdatePerm() {
+  if (deno.platform.os !== "win") {
+    const enc = new TextEncoder();
+    const data = enc.encode("Hello");
+    const filename = deno.makeTempDirSync() + "/test.txt";
+    await deno.writeFile(filename, data, { perm: 0o755 });
+    assertEqual(deno.statSync(filename).mode & 0o777, 0o755);
+    await deno.writeFile(filename, data, { perm: 0o666 });
+    assertEqual(deno.statSync(filename).mode & 0o777, 0o666);
+  }
+});
+
+testPerm({ write: true }, async function writeFileCreate() {
+  const enc = new TextEncoder();
+  const data = enc.encode("Hello");
+  const filename = deno.makeTempDirSync() + "/test.txt";
+  let caughtError = false;
+  // if create turned off, the file won't be created
+  try {
+    await deno.writeFile(filename, data, { create: false });
+  } catch (e) {
+    caughtError = true;
+    assertEqual(e.kind, deno.ErrorKind.NotFound);
+    assertEqual(e.name, "NotFound");
+  }
+  assert(caughtError);
+
+  // Turn on create, should have no error
+  await deno.writeFile(filename, data, { create: true });
+  await deno.writeFile(filename, data, { create: false });
+  const dataRead = deno.readFileSync(filename);
+  const dec = new TextDecoder("utf-8");
+  const actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
+});
+
+testPerm({ write: true }, async function writeFileAppend() {
+  const enc = new TextEncoder();
+  const data = enc.encode("Hello");
+  const filename = deno.makeTempDirSync() + "/test.txt";
+  await deno.writeFile(filename, data);
+  await deno.writeFile(filename, data, { append: true });
+  let dataRead = deno.readFileSync(filename);
+  const dec = new TextDecoder("utf-8");
+  let actual = dec.decode(dataRead);
+  assertEqual("HelloHello", actual);
+  // Now attempt overwrite
+  await deno.writeFile(filename, data, { append: false });
+  dataRead = deno.readFileSync(filename);
+  actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
+  // append not set should also overwrite
+  await deno.writeFile(filename, data);
+  dataRead = deno.readFileSync(filename);
+  actual = dec.decode(dataRead);
+  assertEqual("Hello", actual);
+});