Finding example pointers

These integration tests seek to minimize the use of bespoke data whose representations exist solely within the testing-associated code modules.

Instead of containing custom pointer objects defined inline, the integration tests for this reference implementation use the official pointer examples that are distributed as part of the ethdebug/format/pointer schema itself.

Since JSON Schema does not offer a means by which examples can be named (it only defines a way to represent an ordered list of unlabeled example values), these tests rely on searching for particular examples by their use of uniquely indicative string values (e.g., the "string storage" example pointer is the only example to contain the string "string-storage-contract-variable-slot").

The logic for doing this search is captured by the findExamplePointer() function:

export const findExamplePointer = (() => {
  const {
    schema: {
      examples: examplePointers
    }
  } = describeSchema({
    schema: { id: "schema:ethdebug/format/pointer" }
  }) as { schema: { examples: Pointer[] } };

  return (text: string): Pointer =>
    examplePointers
      .find(pointer => JSON.stringify(pointer).includes(text))!;
})();

(This function is written as an immediately-invoked inline function so as to avoid unnecessary redundant calls to describeSchema().)