test: check custom inspection truncation in assert

[Trott]

The assert module has some truncation logic in a custom inspect
function. This was not covered in tests. Add tests to cover it.

The previously-uncovered lines are

node/lib/internal/assert/assertion_error.js

Lines 437 to 442 in b614840

	if (lines.length > 10) {
	lines.length = 10;
	this[name] = `${lines.join('\n')}\n...`;
	} else if (this[name].length > 512) {
	this[name] = `${this[name].slice(512)}...`;
	}

.

@BridgeAR I could use some confirmation that this is covering a feature and not revealing a bug. When an ASSERTION_ERROR with a long line is inspected, the value in actual or expected will be truncated but the same value will appear in full in the message. Whoops? Or by design?

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

[Trott]

CI: https://ci.nodejs.org/job/node-test-pull-request/23901/

[BridgeAR]

@Trott

@BridgeAR I could use some confirmation that this is covering a feature and not revealing a bug. When an ASSERTION_ERROR with a long line is inspected, the value in actual or expected will be truncated but the same value will appear in full in the message. Whoops? Or by design?

It is by design: we used to only visualize the stack property in case of a fatal exception and other cases. I changed that recently to fully inspect errors on fatal exceptions. Now all properties on an error will be fully inspected. Since the actual and expected values will be visible in the message anyway, it's better to minimize the output for the properties by default, since it would otherwise duplicate the information and that seems pretty verbose. That was the original reason for me to limit the output for these properties.

[BridgeAR]

LGTM. Thanks for writing the tests for this!

[danbev]

Nit: sould -> should

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/23957/

[Trott]

Landed in e3d5257