test: interval analysis unit tests

[hiltontj]

Added unit tests to interval analysis method which converts Expr tree to a set of Intervals for columns in a given schema.

Which issue does this PR close?

I did not have an issue for this, but I was experimenting with the analyze method for converting Expr trees into sets of Intervals and pushed the resulting tests up, since I did not see any that directly tested the analyze method.

Rationale for this change

I did not see any unit tests for the analyze method. In addition to this example, these provide a bit more of a sense of how the method works for different boundary expressions in queries.

What changes are included in this PR?

Two new unit tests in the datafusion/physical-expr/src/analysis.rs module.

Are these changes tested?

Yes.

Are there any user-facing changes?

No.

[hiltontj]

I suspect this is the line that caused the circular dependencies check to fail. I added it so I could get the SessionContext in my test for parsing the SQL expressions - perhaps there is a better way to do that...

[alamb]

I think the way to do so would be to put the test into one of the core integration suites: https://github.com/apache/datafusion/blob/main/datafusion/core/tests/core_integration.rs

Then you run it like

cargo test --test core_integration

Basically SessionContext is in a different crate that depends on this crate (but not the other way around)

[alamb]

Thanks @hiltontj -- this looks quite cool

Maybe @berkaysynnada knows if there are existing tests and/or where the tests could go

[alamb]

I think the way to do so would be to put the test into one of the core integration suites: https://github.com/apache/datafusion/blob/main/datafusion/core/tests/core_integration.rs

Then you run it like

cargo test --test core_integration

Basically SessionContext is in a different crate that depends on this crate (but not the other way around)

[alamb]

Another approach is to avoid parsing SQL and insteadl build these expressions programatically

Like

Suggested change

	("a > 10", Some(11), None),
	(col(a).gt(lit(10), Some(11), None),

There are some other examples here: https://docs.rs/datafusion/latest/datafusion/logical_expr/enum.Expr.html#column-references-and-literals

[hiltontj]

I agree, I think it makes more sense to use the expression helpers for two reasons:

• It brings these tests closer to unit tests and further from integration tests, i.e., no need for SessionContext and SQL parsing
• It removes the need for the circular dependency

I don't mind changing them over to use the helpers.

[hiltontj]

I did just that in a43bf00