assert: improve simple assert

1) If simple assert is called in the very first line of a file and
it causes an error, it used to report the wrong code. The reason
is that the column that is reported is faulty. This is fixed by
subtracting the offset from now on in such cases.

2) The actual code read is now limited to the part that is actually
required to visualize the call site. All other code in e.g. minified
files will not cause a significant overhead anymore.

3) The number of allocations is now significantly lower than it used
to be. The buffer is reused until the correct line in the code is
found. In general the algorithm tries to safe operations where
possible.

4) The indentation is now corrected depending on where the statement
actually beginns.

5) It is now possible to handle `.call()` and `.apply()` properly.

6) The user defined function name will now always be used instead of
only choosing either `assert.ok()` or `assert()`.

PR-URL: https://github.com/nodejs/node/pull/21626
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ben Coe <bencoe@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/test/parallel/test-assert-first-line.js b/test/parallel/test-assert-first-line.js
new file mode 100644
index 0000000000..32eadbf741
--- /dev/null
+++ b/test/parallel/test-assert-first-line.js
@@ -0,0 +1,23 @@
+'use strict';
+
+// Verify that asserting in the very first line produces the expected result.
+
+require('../common');
+const assert = require('assert');
+const { path } = require('../common/fixtures');
+
+assert.throws(
+  () => require(path('assert-first-line')),
+  {
+    name: 'AssertionError [ERR_ASSERTION]',
+    message: "The expression evaluated to a falsy value:\n\n  ässört.ok('')\n"
+  }
+);
+
+assert.throws(
+  () => require(path('assert-long-line')),
+  {
+    name: 'AssertionError [ERR_ASSERTION]',
+    message: "The expression evaluated to a falsy value:\n\n  assert.ok('')\n"
+  }
+);