Add basic EST round-trip testing

cedar-drt/README.md

@@ -13,17 +13,16 @@ The table below lists all available fuzz targets, including which component of t
 | [`abac`](fuzz/fuzz_targets/abac.rs) | Evaluator | DRT | Diff test evaluator on ABAC policies |
 | [`formatter`](fuzz/fuzz_targets/formatter.rs) | Policy formatter, Pretty printer, Parser | PBT | Test round trip property: parse ∘ format ∘ pretty-print == id for ASTs |
 | [`partial-eval`](fuzz/fuzz_targets/partial-eval.rs) | Partial evaluator | PBT | Test that residual policies with unknowns substituted are equivalent to original policies with unknowns replaced |
-| [`pp`](fuzz/fuzz_targets/pp.rs) | Pretty printer, Parser | PBT | Test round trip property: parse ∘ pretty-print == id for ASTs |
 | [`rbac-authorizer`](fuzz/fuzz_targets/rbac-authorizer.rs) | Authorizer | PBT + DRT | Test for correct authorization responses over a set of simple policies |
 | [`rbac`](fuzz/fuzz_targets/rbac.rs) | Authorizer | DRT | Diff test authorizer on sets of RBAC policies, including template instantiations |
+| [`roundtrip`](fuzz/fuzz_targets/roundtrip.rs) | Pretty printer, Parser, Conversion to JSON | PBT | Test round trip property: parse ∘ pretty-print == deserialize ∘ serialize == id for ASTs |
 | [`simple-parser`](fuzz/fuzz_targets/simple-parser.rs) |  Parser | PBT | Test that parsing doesn't crash with random input strings |
 | [`strict-validation-drt-type-directed`](fuzz/fuzz_targets/strict-validation-drt-type-directed.rs) | Validator | DRT | Diff test strict validation using (mostly) well-typed inputs |
 | [`validation-drt-type-directed`](fuzz/fuzz_targets/validation-drt-type-directed.rs) | Validator | DRT | Diff test permissive validation using (mostly) well-typed inputs |
 | [`validation-drt`](fuzz/fuzz_targets/validation-drt.rs) | Validator | DRT | Diff test permissive validation |
 | [`validation-pbt`](fuzz/fuzz_targets/validation-pbt.rs) | Validator | PBT | Test that validated policies do not result in type errors |
 | [`wildcard-matching`](fuzz/fuzz_targets/wildcard-matching.rs) | String matching algorithm used for the `like` operator | DRT | Diff test wildcard matching using a regex-based implementation |
 
-
 ## Logging
 
 If the fuzz targets are compiled with the `log` features, then they will log their entire corpus to the file pointed at in the `LOGFILE` environment variable.
@@ -34,6 +33,7 @@ The sampling rate can be controlled by the `RATE` environment variable, which de
 When using the `abac` or `abac-type-directed` targets, you can set `DUMP_TEST_DIR` and `DUMP_TEST_NAME` to have the fuzzer write out inputs in the format used by our [integration tests](https://github.com/cedar-policy/cedar/tree/main/cedar-integration-tests).
 The `create_corpus.sh` script will run the fuzzer for a set amount of time and then write the (minimized) corpus inputs into a folder using the integration test format.
 You can adjust the script's behavior using the following environment variables:
+
 * `FUZZ_TARGET`: `abac` or `abac-type-directed` (default = `abac`)
 * `TIMEOUT`: how long to run (default = 15m)
 * `JOBS`: number of jobs (default = 4)
@@ -42,8 +42,9 @@ You can adjust the script's behavior using the following environment variables:
 ## Debugging build failures
 
 If you run into weird build issues,
+
 1. Make sure you have run `source set_env_vars.sh`, which sets all the environment variables needed to run the Dafny and Lean definitional code.
 2. Try a `cargo clean` and rebuild.
 3. If the steps above don't help, then file [an issue](https://github.com/cedar-policy/cedar-spec/issues).
 
-If everything builds, but the integration tests are failing, then it may be helpful to set `RUST_BACKTRACE=1` and run `cargo test -- --nocapture` to print additional test information.
+If everything builds, but the integration tests are failing, then it may be helpful to set `RUST_BACKTRACE=1` and run `cargo test -- --nocapture` to print additional test information.

cedar-drt/fuzz/Cargo.toml

@@ -92,8 +92,8 @@ test = false
 doc = false
 
 [[bin]]
-name = "pp"
-path = "fuzz_targets/pp.rs"
+name = "roundtrip"
+path = "fuzz_targets/roundtrip.rs"
 test = false
 doc = false