Add JSONSchema generation support for supergraph.yaml files (#582)

This was done as a one-off for our extension (which will soon include
validation for `supergraph.yaml` files!), but I figure we should keep it
around so we can regenerate again in the future.

We can/should also add a command in `rover` to do this, similar to the
equivalent of `router`, so folks can generate schemas for their IDEs of
choice.

Removes `camino` because it is not supported by `schemars`.

apollo-federation-types/CHANGELOG.md

@@ -2,15 +2,21 @@
 
 Not every version is listed here because versions before 0.14.0 did not have a changelog.
 
-## 0.15.0 (Unreleased)
+## 0.15.0 - Unreleased
 
 ### Breaking changes
 
 - `GraphQLError.nodes` is now an `Option<Vec<SubgraphASTNode>>`
+- All usages of `camino::Utf8PathBuf` have been replaced with `std::path::PathBuf`
+
+### Features
+
+- A new `json_schema` feature derives the `schemars::JsonSchema` trait on `SupergraphConfig` and its sub-types.
 
 ## 0.14.1 - 2024-09-19
 
 ### Features
+
 - `impl FromIterator<(String, SubgraphConfig)> for SupergraphConfig`
 
 ## 0.14.0 - 2024-09-11

apollo-federation-types/Cargo.toml

@@ -15,14 +15,15 @@ default = ["config", "build", "build_plugin"]
 
 build = ["serde_json"]
 build_plugin = ["serde_json"]
-config = ["camino", "log", "thiserror", "serde_yaml", "url", "serde_with"]
+config = ["log", "thiserror", "serde_yaml", "url", "serde_with"]
+json_schema = ["schemars"]
 
 [dependencies]
 # config and build dependencies
 serde = { version = "1", features = ["derive"] }
+schemars = { version = "0.8.21", optional = true, features = ["url"]}
 
 # config-only dependencies
-camino = { version = "1", features = ["serde1"], optional = true }
 log = { version = "0.4", optional = true }
 semver = { version = "1", features = ["serde"] }
 serde_with = { version = "3", default-features = false, features = ["macros"], optional = true }

apollo-federation-types/src/config/subgraph.rs

@@ -1,10 +1,11 @@
-use camino::Utf8PathBuf;
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
+use std::path::PathBuf;
 use url::Url;
 
 /// Config for a single [subgraph](https://www.apollographql.com/docs/federation/subgraphs/)
 #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 pub struct SubgraphConfig {
     /// The routing URL for the subgraph.
     /// This will appear in supergraph SDL and
@@ -37,10 +38,11 @@ impl SubgraphConfig {
 // this is untagged, meaning its fields will be flattened into the parent
 // struct when de/serialized. There is no top level `schema_source`
 // in the configuration.
+#[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 #[serde(untagged)]
 pub enum SchemaSource {
     File {
-        file: Utf8PathBuf,
+        file: PathBuf,
     },
     SubgraphIntrospection {
         subgraph_url: Url,

apollo-federation-types/src/config/supergraph.rs

@@ -1,6 +1,5 @@
-use std::{collections::BTreeMap, fs};
+use std::{collections::BTreeMap, fs, path::PathBuf};
 
-use camino::Utf8PathBuf;
 use serde::{Deserialize, Serialize};
 
 use crate::{
@@ -11,6 +10,7 @@ use crate::{
 /// The configuration for a single supergraph
 /// composed of multiple subgraphs.
 #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(feature = "json_schema", derive(schemars::JsonSchema))]
 pub struct SupergraphConfig {
     // Store config in a BTreeMap, as HashMap is non-deterministic.
     subgraphs: BTreeMap<String, SubgraphConfig>,
@@ -55,13 +55,11 @@ impl SupergraphConfig {
     }
 
     /// Create a new SupergraphConfig from a YAML file.
-    pub fn new_from_yaml_file<P: Into<Utf8PathBuf>>(
-        config_path: P,
-    ) -> ConfigResult<SupergraphConfig> {
-        let config_path: Utf8PathBuf = config_path.into();
+    pub fn new_from_yaml_file<P: Into<PathBuf>>(config_path: P) -> ConfigResult<SupergraphConfig> {
+        let config_path: PathBuf = config_path.into();
         let supergraph_yaml =
             fs::read_to_string(&config_path).map_err(|e| ConfigError::MissingFile {
-                file_path: config_path.to_string(),
+                file_path: config_path.display().to_string(),
                 message: e.to_string(),
             })?;
 
@@ -177,15 +175,13 @@ impl FromIterator<(String, SubgraphConfig)> for SupergraphConfig {
 
 #[cfg(test)]
 mod tests {
-    use std::{collections::BTreeMap, convert::TryFrom, fs};
+    use std::{collections::BTreeMap, convert::TryFrom, fs, path::PathBuf};
 
     use assert_fs::TempDir;
-    use camino::Utf8PathBuf;
     use semver::Version;
 
-    use crate::config::{FederationVersion, SchemaSource, SubgraphConfig};
-
     use super::SupergraphConfig;
+    use crate::config::{FederationVersion, SchemaSource, SubgraphConfig};
 
     #[test]
     fn it_can_parse_valid_config_without_version() {
@@ -513,7 +509,7 @@ subgraphs:
 "#;
 
         let tmp_home = TempDir::new().unwrap();
-        let mut config_path = Utf8PathBuf::try_from(tmp_home.path().to_path_buf()).unwrap();
+        let mut config_path = PathBuf::try_from(tmp_home.path().to_path_buf()).unwrap();
         config_path.push("config.yaml");
         fs::write(&config_path, raw_good_yaml).unwrap();
 

apollo-federation-types/src/config/version.rs

@@ -1,12 +1,16 @@
-use std::{
-    fmt::{self, Display},
-    str::FromStr,
+#[cfg(feature = "json_schema")]
+use schemars::{
+    gen::SchemaGenerator,
+    schema::{Schema, SchemaObject},
 };
-
 use semver::Version;
 use serde::de::Error;
 use serde::{Deserialize, Deserializer};
 use serde_with::{DeserializeFromStr, SerializeDisplay};
+use std::{
+    fmt::{self, Display},
+    str::FromStr,
+};
 
 use crate::config::ConfigError;
 
@@ -200,6 +204,19 @@ impl FromStr for FederationVersion {
     }
 }
 
+#[cfg(feature = "json_schema")]
+impl schemars::JsonSchema for FederationVersion {
+    fn schema_name() -> String {
+        String::from("FederationVersion")
+    }
+
+    fn json_schema(_gen: &mut SchemaGenerator) -> Schema {
+        let mut schema = SchemaObject::default();
+        schema.string().pattern = Some(r#"^(1|2|=2\.\d+\.\d+.*)$"#.to_string());
+        schema.into()
+    }
+}
+
 impl<'de> Deserialize<'de> for FederationVersion {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
     where