GIDL

GIDL is a code generation tool to create Golden FIDL Tests. The focus is encoding and decoding tests, to ensure that various bindings properly follow the wire format specification.

Using GIDL

Regenerate conformance tests:

fx full-build && ./tools/fidl/gidl-conformance-suite/regen.sh

Writing Conformance Tests

There are three kinds of tests which can be expressed. We describe them below.

Success

A success test case captures a value (optionally with handles), and its wire format representation.

Here is an example:

success("OneStringOfMaxLengthFive-empty") {
    value = OneStringOfMaxLengthFive {
        the_string: "",
    }
    bytes = {
        0, 0, 0, 0, 0, 0, 0, 0, // length
        255, 255, 255, 255, 255, 255, 255, 255, // alloc present
    }
}

From this description, the following must be verified:

• Encoding of the value into bytes
• Decoding of the bytes into the value
• Rountrips from value to bytes, back to value, back to bytes

Fails to Encode

A fails_to_encode test case captures a value (optionally with handles), which fails to encode (e.g. constraints not met).

Here is an example:

fails_to_encode("OneStringOfMaxLengthFive-too-long") {
    value = OneStringOfMaxLengthFive {
        the_string: "bonjour", // 6 characters
    }
    err = FIDL_STRING_TOO_LONG
}

From this description, the following must be verified:

• Encoding of the value fails
• Failure triggers exactly the expected error

Fails to Decode

A fails_to_decode test case captures bytes encoding (optionally with handles), which fails to decode (e.g. incorrect wire encoding).

Here is an example:

fails_to_decode("OneStringOfMaxLengthFive-wrong-lenght") {
    bytes = {
        1, 0, 0, 0, 0, 0, 0, 0, // length
        255, 255, 255, 255, 255, 255, 255, 255, // alloc present
        // one character missing
    }
    err = FIDL_STRING_INCORRECT_SIZE
}

From this description, the following must be verified:

• Decoding of the bytes encoding fails
• Failure triggers exactly the expected error