reorganize some code in anticipation of some larger changes (#40)

progenitor-impl/src/util.rs

@@ -0,0 +1,86 @@
+// Copyright 2022 Oxide Computer Company
+
+use convert_case::{Case, Casing};
+use indexmap::IndexMap;
+use openapiv3::{
+    Components, Parameter, ReferenceOr, RequestBody, Response, Schema,
+};
+use unicode_xid::UnicodeXID;
+
+use crate::Result;
+
+pub(crate) trait ReferenceOrExt<T: ComponentLookup> {
+    fn item<'a>(&'a self, components: &'a Option<Components>) -> Result<&'a T>;
+}
+pub(crate) trait ComponentLookup: Sized {
+    fn get_components(
+        components: &Components,
+    ) -> &IndexMap<String, ReferenceOr<Self>>;
+}
+
+impl<T: ComponentLookup> ReferenceOrExt<T> for openapiv3::ReferenceOr<T> {
+    fn item<'a>(&'a self, components: &'a Option<Components>) -> Result<&'a T> {
+        match self {
+            ReferenceOr::Item(item) => Ok(item),
+            ReferenceOr::Reference { reference } => {
+                let idx = reference.rfind('/').unwrap();
+                let key = &reference[idx + 1..];
+                let parameters =
+                    T::get_components(components.as_ref().unwrap());
+                parameters.get(key).unwrap().item(components)
+            }
+        }
+    }
+}
+
+impl ComponentLookup for Parameter {
+    fn get_components(
+        components: &Components,
+    ) -> &IndexMap<String, ReferenceOr<Self>> {
+        &components.parameters
+    }
+}
+
+impl ComponentLookup for RequestBody {
+    fn get_components(
+        components: &Components,
+    ) -> &IndexMap<String, ReferenceOr<Self>> {
+        &components.request_bodies
+    }
+}
+
+impl ComponentLookup for Response {
+    fn get_components(
+        components: &Components,
+    ) -> &IndexMap<String, ReferenceOr<Self>> {
+        &components.responses
+    }
+}
+
+impl ComponentLookup for Schema {
+    fn get_components(
+        components: &Components,
+    ) -> &IndexMap<String, ReferenceOr<Self>> {
+        &components.schemas
+    }
+}
+
+pub(crate) fn sanitize(input: &str, case: Case) -> String {
+    let out = input
+        .replace("'", "")
+        .replace(|c: char| !c.is_xid_continue(), "-")
+        .to_case(case);
+
+    let out = match out.chars().next() {
+        None => "x".to_case(case),
+        Some(c) if c.is_xid_start() => out,
+        Some(_) => format!("_{}", out),
+    };
+
+    // Make sure the string is a valid Rust identifier.
+    if syn::parse_str::<syn::Ident>(&out).is_ok() {
+        out
+    } else {
+        format!("{}_", out)
+    }
+}