Teacher tool: field value validator added

[srietkerk]

A validator that checks the field values of a block has been added to our validator library. Field values are a specific type of input for a block. The easiest type that I can demonstrate is the different operators that are associated with the math_arithmetic block. In this case, the field value type is "OP" or, I'm guessing, the shorthand for operation. Some others that I've seen in blocklycompiler.ts are: TEXT, EXPRESSION, VAR, BOOL, NAME, VALUE and more. The "OP" field value for the math_arithmetic block can be ADD, MINUS, MULTIPLY, DIVIDE and more.

You'll see that the validation I made for logic_compare is looking for something very specific. The logic_compare blocks in the following program don't pass because the one that has the EQ "OP" type doesn't have two math_number blocks, and the other that has two numbers has a different "OP" type.

Edit: And to show that it can pass lol

One thing to note about this approach is that if we want to support any type of field value, we need to know that field value's name and possible values it can be before we can create the validator for it. @riknoll chatted with me and let me know that this will require quite a bit of work because all of our custom blocks have field value names that are going to be tricky to find. He recommended a way for me to find the different field values, which isn't hard, just tedious. I'm planning on making a table in OneNote that will have the relationship between a block, it's field value names, and the variations that a specific field value can have. For now, I'm planning to build this table as I go, but we might reach a time when we'll want to just fill the table as earnestly as possible.

[eanders-ms]

Very nice! Made one small suggestion.

I agree building the table as we go is fine for now. We will want to put this info in a publicly visible doc at some point as part of documenting the process for writing validator plans.