Realign expressions and assertion methods

[BernieWhite]

Discussed in #904

^{Originally posted by BernieWhite January 7, 2022}
Across expressions (used in YAML and JSON resources) and assertion methods (used in PowerShell resources) there are different names used to equivalent functionality. While terminology differs between programming/ scripting languages we want to make it even easier to understand and author rules.

We should look to realign naming to be ideally the same for expressions and assertion methods.

This discussion proposes the following naming changes.

Expression	Assertion method	Proposed change
Contains	Contains	No change
Count	Count	No change
Equals	n/a	See note (1)
EndsWith	EndsWith	No change
Exists	HasField	Rename assertion method to Exists.
Greater	Greater	No change
GreaterOrEquals	GreaterOrEqual	Rename expression to GreaterOrEqual.
HasDefault	HasDefaultValue	Rename assertion method to HasDefault.
HasSchema	HasJsonSchema	Rename assertion method to HasSchema.
HasValue	n/a	See note (1).
In	In	No change
IsLower	IsLower	No change
IsString	IsString	No change
IsUpper	IsUpper	No change
Less	Less	No change
LessOrEquals	LessOrEqual	Rename expression to LessOrEqual.
Match	Match	No change
NotEquals	n/a	No change
NotIn	NotIn	No change
NotMatch	NotMatch	No change
SetOf	SetOf	No change
StartsWith	StartsWith	No change
Subset	Subset	No change
Version	Version	No change
n/a	FileHeader	No change
n/a	FilePath	No change
n/a	HasFields	No change
n/a	HasFieldValue	See note (1)
IsArray	IsArray	See note (2)
IsBoolean	IsBoolean	See note (2)
IsDateTime	IsDateTime	See note (2)
IsInteger	IsInteger	See note (2)
IsNumeric	IsNumeric	See note (2)
n/a	JsonSchema	No change
n/a	NotHasField	No change
n/a	NotNull	No change
NotWithinPath	NotWithinPath	See note (3)
n/a	Null	No change
n/a	NullOrEmpty	No change
n/a	TypeOf	No change
WithinPath	WithinPath	See note (3)

• (1) The Equals, HasValue and expression and HasFieldValue are approximate. Also these are not necessarily intuitive.
  • It may be better to introduce Empty, NotEmpty, and Equal across expressions and assertion methods. Then deprecate Equals, HasValue and HasFieldValue.
• (2) Added in Add expression support for type based assertions #908.
• (3) Added in Add a source expression property #933.

https://microsoft.github.io/PSRule/v2/concepts/PSRule/en-US/about_PSRule_Expressions/#hasvalue
https://microsoft.github.io/PSRule/v2/concepts/PSRule/en-US/about_PSRule_Expressions/#equals
https://microsoft.github.io/PSRule/v2/concepts/PSRule/en-US/about_PSRule_Assert/#hasfieldvalue