CMTK0005 reports a multidimensional array with a zero dimension, such as new Plain[0, 2], which holds no element #227

Reported by an external review of release/2.3.1 @ dbdd44e, which reproduced it; the cause confirmed here by reading the source, not yet run.

Package

CodoMetis.TypeKit.Analyzers

Version

2.3.0 (the same code in v2.3.0), and release/2.3.1 @ dbdd44e

How does it fail?

Loudly. A warning on an array that holds no element

Problem

DefaultFilledCollectionAnalyzer.AnalyzeArrayCreation (src/CodoMetis.TypeKit.Analyzers/DefaultFilledCollectionAnalyzer.cs:69) skips an empty array only when every dimension is a constant 0 (All). A multidimensional array is empty when any dimension is 0, so new Plain[0, 2] holds no default value object and is reported.

Scenario

var none = new Plain[0, 2];   // CMTK0005; expected: nothing, it has no elements
var also = new Plain[2, 0];   // the same
var some = new Plain[2, 2];   // CMTK0005, rightly

stackalloc (:110) has one dimension, where All and Any agree.

Change

Any in place of All at :69. A Warning reporting less needs no exception to decision 34.

Test

CMTK0005 rows for [0, 2], [2, 0], [0, 0], a jagged [0][] and [2, 2], the last reported; reverted per verify-the-guard. Input class: an array creation of a value object, by rank and which dimension is a constant zero.

Environment

.NET SDK 10.0.4xx; any consumer.