test: add and use tmpdir.hasEnoughSpace()

test/common/README.md

@@ -1030,6 +1030,15 @@ Avoid calling it more than once in an asynchronous context as one call
 might refresh the temporary directory of a different context, causing
 the test to fail somewhat mysteriously.
 
+### `hasEnoughSpace(size)`
+
+* `size` [\<number>][<number>] Required size, in bytes.
+
+Returns `true` if the available blocks of the file system underlying `path`
+are likely sufficient to hold a single file of `size` bytes. This is useful for
+skipping tests that require hundreds of megabytes or even gigabytes of temporary
+files, but it is inaccurate and susceptible to race conditions.
+
 ## UDP pair helper
 
 The `common/udppair` module exports a function `makeUDPPair` and a class

test/common/tmpdir.js

@@ -69,7 +69,13 @@ function onexit(useSpawn) {
   }
 }
 
+function hasEnoughSpace(size) {
+  const { bavail, bsize } = fs.statfsSync(tmpPath);
+  return bavail >= Math.ceil(size / bsize);
+}
+
 module.exports = {
   path: tmpPath,
   refresh,
+  hasEnoughSpace,
 };

test/parallel/test-fs-promises-file-handle-readFile.js

@@ -106,17 +106,22 @@ async function doReadAndCancel() {
     // Variable taken from https://github.com/nodejs/node/blob/1377163f3351/lib/internal/fs/promises.js#L5
     const kIoMaxLength = 2 ** 31 - 1;
 
-    const newFile = path.resolve(tmpDir, 'dogs-running3.txt');
-    await writeFile(newFile, Buffer.from('0'));
-    await truncate(newFile, kIoMaxLength + 1);
-
-    const fileHandle = await open(newFile, 'r');
-
-    await assert.rejects(fileHandle.readFile(), {
-      name: 'RangeError',
-      code: 'ERR_FS_FILE_TOO_LARGE'
-    });
-    await fileHandle.close();
+    if (!tmpdir.hasEnoughSpace(kIoMaxLength)) {
+      // truncate() will fail with ENOSPC if there is not enough space.
+      common.printSkipMessage(`Not enough space in ${tmpDir}`);
+    } else {
+      const newFile = path.resolve(tmpDir, 'dogs-running3.txt');
+      await writeFile(newFile, Buffer.from('0'));
+      await truncate(newFile, kIoMaxLength + 1);
+
+      const fileHandle = await open(newFile, 'r');
+
+      await assert.rejects(fileHandle.readFile(), {
+        name: 'RangeError',
+        code: 'ERR_FS_FILE_TOO_LARGE'
+      });
+      await fileHandle.close();
+    }
   }
 }
 

test/parallel/test-fs-readfile.js

@@ -52,21 +52,27 @@ for (const e of fileInfo) {
     assert.deepStrictEqual(buf, e.contents);
   }));
 }
-// Test readFile size too large
+
+// readFile() and readFileSync() should fail if the file is too big.
 {
   const kIoMaxLength = 2 ** 31 - 1;
 
-  const file = path.join(tmpdir.path, `${prefix}-too-large.txt`);
-  fs.writeFileSync(file, Buffer.from('0'));
-  fs.truncateSync(file, kIoMaxLength + 1);
+  if (!tmpdir.hasEnoughSpace(kIoMaxLength)) {
+    // truncateSync() will fail with ENOSPC if there is not enough space.
+    common.printSkipMessage(`Not enough space in ${tmpdir.path}`);
+  } else {
+    const file = path.join(tmpdir.path, `${prefix}-too-large.txt`);
+    fs.writeFileSync(file, Buffer.from('0'));
+    fs.truncateSync(file, kIoMaxLength + 1);
 
-  fs.readFile(file, common.expectsError({
-    code: 'ERR_FS_FILE_TOO_LARGE',
-    name: 'RangeError',
-  }));
-  assert.throws(() => {
-    fs.readFileSync(file);
-  }, { code: 'ERR_FS_FILE_TOO_LARGE', name: 'RangeError' });
+    fs.readFile(file, common.expectsError({
+      code: 'ERR_FS_FILE_TOO_LARGE',
+      name: 'RangeError',
+    }));
+    assert.throws(() => {
+      fs.readFileSync(file);
+    }, { code: 'ERR_FS_FILE_TOO_LARGE', name: 'RangeError' });
+  }
 }
 
 {

test/pummel/test-fs-readfile-tostring-fail.js

@@ -16,6 +16,10 @@ if (common.isAIX && (Number(cp.execSync('ulimit -f')) * 512) < kStringMaxLength)
 const tmpdir = require('../common/tmpdir');
 tmpdir.refresh();
 
+if (!tmpdir.hasEnoughSpace(kStringMaxLength)) {
+  common.skip(`Not enough space in ${tmpdir.path}`);
+}
+
 const file = path.join(tmpdir.path, 'toobig.txt');
 const stream = fs.createWriteStream(file, {
   flags: 'a',