smithy-rs/rust-runtime/aws-smithy-json/TESTING.md

How to run JSONTestSuite against aws-smithy-json deserialize

When making changes to the deserialize module, it is a good idea to run the changes against the JSONTestSuite and manually examine the test results.

How to setup the JSONTestSuite

1. Clone the JSONTestSuite repository.
2. In JSONTestSuite/parsers, create a new Cargo bin project named test_json-aws_smithy_json.
3. Add the following dependencies to the Cargo.toml (be sure to replace <local-path-to-smithy-rs>:

aws-smithy-json = { path = "<local-path-to-smithy-rs>/rust-runtime/aws-smithy-json" }

4. Replace the code in main.rs with:

use std::fs::File;
use std::io::Read;
use std::env;

use aws_smithy_json::deserialize::{json_token_iter, Token, Error};

fn main() {
    let args: Vec<_> = env::args().collect();
    if args.len() != 2 {
        println!("Usage: {} file.json", args[0]);
        std::process::exit(1);
    }

    let ref path = args[1];
    let mut s = String::new();
    let mut f = File::open(path).expect("Unable to open file");
    match f.read_to_string(&mut s) {
        Err(_) => std::process::exit(1),
        Ok(_) => println!("{}", s),
    }

    let result: Result<Vec<Token>, Error> = json_token_iter(s.as_bytes()).collect();
    match result {
        Err(_) => std::process::exit(1),
        Ok(value) => if value.is_empty() {
            std::process::exit(1)
        } else {
            // The test suite includes incomplete objects and arrays (i.e., "[null,").
            // These are completely valid for this parser, so we'll just pretend to have
            // failed to parse these to satisfy the test suite.
            if value.first() == Some(&Token::StartObject) && value.last() != Some(&Token::EndObject) {
                std::process::exit(1)
            }
            if value.first() == Some(&Token::StartArray) && value.last() != Some(&Token::EndArray) {
                std::process::exit(1)
            }
            // Unescape all strings and fail if any of them failed to unescape.
            for token in value {
                if let Token::ValueString(escaped) = token {
                    if escaped.into_unescaped().is_err() {
                        std::process::exit(1)
                    }
                }
            }
            std::process::exit(0)
        }
    }
}

5. Compile this program with cargo build --release.
6. Modify JSONTestSuite/run_tests.py so that the programs dictionary only contains this one entry:

programs = {
   "Rust aws-smithy-json":
       {
           "url":"dontcare",
           "commands":[os.path.join(PARSERS_DIR, "test_json-aws_smithy_json/target/release/sj")]
       }
}

7. Run run_tests.py and examine the output with a web browser by opening JSONTestSuite/results/parsing.html.

Examining the results

When looking at JSONTestSuite/results/parsing.html, there is a matrix of test cases against their results with a legend at the top.

Any test result marked with blue or light blue is for a test case where correct behavior isn't specified, so use your best judgement to decide if it should have succeeded or failed.

The other colors are bad and should be carefully examined. At time of writing, the following test cases succeed when they should fail, and we intentionally left it that way since we're not currently concerned about being more lenient in the number parsing:

n_number_-01.json                           [-01]
n_number_-2..json                           [-2.]
n_number_0.e1.json                          [0.e1]
n_number_2.e+3.json                         [2.e+3]
n_number_2.e-3.json                         [2.e-3]
n_number_2.e3.json                          [2.e3]
n_number_neg_int_starting_with_zero.json    [-012]
n_number_neg_real_without_int_part.json     [-.123]
n_number_real_without_fractional_part.json  [1.]
n_number_with_leading_zero.json             [012]

This test case succeeds with our parser and that's OK since we're a token streaming parser (multiple values are allowed):

n_structure_double_array.json               [][]