patternProperties?

Hello:

Cool project! I started implementing it into a sort of repo-management-type software I'm working on. However, typify didn't quite do what I expected, and looking into it, doesn't seem to support JSON Schema's patternProperties. I'm using YAML, where for example, I have a file like this:

variables:
  BRANCH_GROUP_A: main
  BRANCH_GROUP_B: feature/beta
  SOMETHINGELSE: "123"
repos:
  thing:
    branch: hotfix/BUG-1234
    commit: HEAD
  some-code:
    branch: ${BRANCH_GROUP_A}
    commit: HEAD
  doesnt-matter:
    branch: ${BRANCH_GROUP_A}
    commit: 7f9329dc0741a4eeea209497f4e03513454e7606
  meta-star:
    branch: ${BRANCH_GROUP_B}
    commit: da9063bdfbe130f424ba487f167da68e0ce90e7d

I could argue for the repos section to convert that to a list instead of an object and add an extra "name: xyz" field, but that just adds more boilerplate, but variables definitely doesn't make much sense to do anything other than the current format.

So the JSON schema looks like this:

{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "$id": "https://example.com/snapshot.json",
    "title": "snapshot",
    "description": "Schema for SNAPSHOT",
    "type": "object",
    "properties": {
        "variables": {
            "type": "object",
            "patternProperties": {
                "^[A-Z_]+$": {
                    "$comment": "Variable names uppercase and underscores only, value any string",
                    "type": "string"
                }
            },
            "additionalProperties": false,
            "minProperties": 1,
            "uniqueItems": true
        },
        "repos": {
            "type": "object",
            "patternProperties": {
                "^[a-z_-]+$": {
                    "$comment": "Repo names lowercase only, object types",
                    "type": "object",
                    "properties": {
                        "branch": { "type": "string" },
                        "commit": { "type": "string" }
                    },
                    "required": ["branch", "commit"]
                }
            },
            "additionalProperties": false,
            "minProperties": 1,
            "uniqueItems": true
        }
    },
    "required": ["repos"],
    "additionalProperties": false
}

I integrated typify with build.rs, but get the same results with cargo typify ./snapshot.json, small example (which I believe is correct?):

let str_snapshot_content = std::fs::read_to_string("./test_snapshot.yaml").unwrap();
let test = serde_yaml::from_str::<snapshot::Snapshot>(&str_snapshot_content).unwrap();

And panicking at the second line, as I now expect, since it doesn't know what to look for:

thread 'main' panicked at src/main.rs:68:72:
called `Result::unwrap()` on an `Err` value: Error("variables: unknown field `BRANCH_GROUP_A`, there are no fields", line: 2, column: 3)

Also, various unused variable warnings in the generated code file:

warning: unused variable: `value`
   --> <snip>/out/gen_schema_types.rs:254:17
    |
254 |                 value: SnapshotRepos,
    |                 ^^^^^ help: if this is intentional, prefix it with an underscore: `_value`
    |
    = note: `#[warn(unused_variables)]` on by default

Anyway, I didn't see an existing issue for this, so figured I'd open one! Thanks!

Start by reproducing the failure with snapshot.json, build.rs, src/main.rs, and test_snapshot.yaml, then inspect the generated out/gen_schema_types.rs around the reported warning. Trace how patternProperties is represented for variables and repos and how serde_yaml deserializes the generated types. Done means the example deserializes successfully and the reported unused-variable warnings are addressed.