feat: Support mustache on link directives

src/core/config/reader.rs

@@ -40,6 +40,12 @@ impl ConfigReader {
         config_module: ConfigModule,
         parent_dir: Option<&'async_recursion Path>,
     ) -> anyhow::Result<ConfigModule> {
+        let reader_ctx = ConfigReaderContext {
+            runtime: &self.runtime,
+            vars: &Default::default(),
+            headers: Default::default(),
+        };
+
         let links: Vec<Link> = config_module
             .config()
             .links
@@ -65,7 +71,11 @@ impl ConfigReader {
 
             match link.type_of {
                 LinkType::Config => {
-                    let source = self.resource_reader.read_file(path).await?;
+                    let source = self
+                        .resource_reader
+                        .read_file(path)
+                        .await?
+                        .render(&reader_ctx);
                     let content = source.content;
                     let config = Config::from_source(Source::detect(&source.path)?, &content)?;
                     config_module = config_module.and_then(|config_module| {
@@ -184,7 +194,20 @@ impl ConfigReader {
         &self,
         files: &[T],
     ) -> anyhow::Result<ConfigModule> {
-        let files = self.resource_reader.read_files(files).await?;
+        let reader_ctx = ConfigReaderContext {
+            runtime: &self.runtime,
+            vars: &Default::default(),
+            headers: Default::default(),
+        };
+
+        let files = self
+            .resource_reader
+            .read_files(files)
+            .await?
+            .into_iter()
+            .map(|file| file.render(&reader_ctx))
+            .collect::<Vec<_>>();
+
         let mut config_module = Valid::succeed(ConfigModule::default());
 
         for file in files.iter() {

src/core/mustache/eval.rs

@@ -100,14 +100,27 @@ impl Mustache {
         PathStringEval::new().eval(self, value)
     }
 
+    pub fn partial_render(&self, value: &impl PathString) -> String {
+        self.segments()
+            .iter()
+            .map(|segment| match segment {
+                Segment::Literal(text) => text.to_string(),
+                Segment::Expression(parts) => {
+                    value.path_string(parts).map(|v| v.to_string()).unwrap_or(
+                        Mustache::from(vec![Segment::Expression(parts.to_vec())]).to_string(),
+                    )
+                }
+            })
+            .collect()
+    }
+
     pub fn render_graphql(&self, value: &impl PathGraphql) -> String {
         PathGraphqlEval::new().eval(self, value)
     }
 }
 
 #[cfg(test)]
 mod tests {
-
     mod render {
         use std::borrow::Cow;
 

src/core/mustache/model.rs

@@ -62,7 +62,7 @@ impl Display for Mustache {
             .iter()
             .map(|segment| match segment {
                 Segment::Literal(text) => text.clone(),
-                Segment::Expression(parts) => format!("{{{{{}}}}}", parts.join(".")),
+                Segment::Expression(parts) => format!("{{{{.{}}}}}", parts.join(".")),
             })
             .collect::<Vec<String>>()
             .join("");

src/core/mustache/parse.rs

@@ -88,14 +88,14 @@ mod tests {
     #[test]
     fn test_to_string() {
         let expectations = vec![
-            r"/users/{{value.id}}/todos",
-            r"http://localhost:8090/{{foo.bar}}/api/{{hello.world}}/end",
-            r"http://localhost:{{args.port}}",
-            r"/users/{{value.userId}}",
-            r"/bar?id={{args.id}}&flag={{args.flag}}",
-            r"/foo?id={{value.id}}",
-            r"{{value.d}}",
-            r"/posts/{{args.id}}",
+            r"/users/{{.value.id}}/todos",
+            r"http://localhost:8090/{{.foo.bar}}/api/{{.hello.world}}/end",
+            r"http://localhost:{{.args.port}}",
+            r"/users/{{.value.userId}}",
+            r"/bar?id={{.args.id}}&flag={{.args.flag}}",
+            r"/foo?id={{.value.id}}",
+            r"{{.value.d}}",
+            r"/posts/{{.args.id}}",
             r"http://localhost:8000",
         ];
 

src/core/resource_reader.rs

@@ -7,7 +7,9 @@ use futures_util::TryFutureExt;
 use tailcall_hasher::TailcallHasher;
 use url::Url;
 
+use crate::core::config::ConfigReaderContext;
 use crate::core::runtime::TargetRuntime;
+use crate::core::Mustache;
 
 /// Response of a file read operation
 #[derive(Debug)]
@@ -16,6 +18,14 @@ pub struct FileRead {
     pub path: String,
 }
 
+impl FileRead {
+    pub fn render(mut self, reader_context: &ConfigReaderContext) -> Self {
+        let schema = Mustache::parse(&self.content).partial_render(reader_context);
+        self.content = schema;
+        self
+    }
+}
+
 /// Supported Resources by Resource Reader
 pub enum Resource {
     RawPath(String),

tests/core/snapshots/env-value.md_merged.snap

@@ -14,7 +14,7 @@ type Post {
 }
 
 type Query {
-  post1: Post @http(url: "http://jsonplaceholder.typicode.com/posts/{{.env.ID}}")
-  post2: Post @http(url: "http://jsonplaceholder.typicode.com/posts/{{.env.POST_ID}}")
-  post3: Post @http(url: "http://jsonplaceholder.typicode.com/posts/{{.env.NESTED_POST_ID}}")
+  post1: Post @http(url: "http://jsonplaceholder.typicode.com/posts/1")
+  post2: Post @http(url: "http://jsonplaceholder.typicode.com/posts/2")
+  post3: Post @http(url: "http://jsonplaceholder.typicode.com/posts/3")
 }

tests/core/snapshots/test-eval-strict.md_client.snap

@@ -0,0 +1,22 @@
+---
+source: tests/core/spec.rs
+expression: formatted
+---
+type Post {
+  foo: String
+  id: Int!
+  user: User
+  userId: Int!
+}
+
+type Query {
+  post(id: Int!): [Post]
+}
+
+type User {
+  id: Int!
+}
+
+schema {
+  query: Query
+}

tests/core/snapshots/test-eval-strict.md_merged.snap

@@ -0,0 +1,22 @@
+---
+source: tests/core/spec.rs
+expression: formatter
+---
+schema @server(port: 8080) @upstream(batch: {delay: 100, headers: []}, httpCache: 42) {
+  query: Query
+}
+
+type Post {
+  foo: String @http(url: "http://jsonplaceholder.typicode.com/posts/foo")
+  id: Int!
+  user: User @http(url: "http://jsonplaceholder.typicode.com/users/{{.value.userId}}")
+  userId: Int!
+}
+
+type Query {
+  post(id: Int!): [Post] @http(url: "http://jsonplaceholder.typicode.com/posts/{{.args.id}}")
+}
+
+type User {
+  id: Int!
+}

tests/core/snapshots/yaml-nested-unions.md_merged.snap

@@ -34,11 +34,11 @@ union U1 = T1 | T2 | T3
 union U2 = T3 | T4
 
 type Query {
-  testVar0(u: T1Input!): U @http(url: "http://localhost/users/{{args.u}}")
-  testVar1(u: T2Input!): U @http(url: "http://localhost/users/{{args.u}}")
-  testVar2(u: T3Input!): U @http(url: "http://localhost/users/{{args.u}}")
-  testVar3(u: T4Input!): U @http(url: "http://localhost/users/{{args.u}}")
-  testVar4(u: T5Input!): U @http(url: "http://localhost/users/{{args.u}}")
+  testVar0(u: T1Input!): U @http(url: "http://localhost/users/{{.args.u}}")
+  testVar1(u: T2Input!): U @http(url: "http://localhost/users/{{.args.u}}")
+  testVar2(u: T3Input!): U @http(url: "http://localhost/users/{{.args.u}}")
+  testVar3(u: T4Input!): U @http(url: "http://localhost/users/{{.args.u}}")
+  testVar4(u: T5Input!): U @http(url: "http://localhost/users/{{.args.u}}")
 }
 
 type T1 {

tests/core/snapshots/yaml-union-in-type.md_merged.snap

@@ -66,15 +66,15 @@ type NU {
 }
 
 type Query {
-  testVar0Var0(nu: NU__u0!, nnu: NNU__nu0): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar0Var1(nu: NU__u0!, nnu: NNU__nu1): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar0Var2(nu: NU__u0!, nnu: NNU__nu2): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar1Var0(nu: NU__u1!, nnu: NNU__nu0): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar1Var1(nu: NU__u1!, nnu: NNU__nu1): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar1Var2(nu: NU__u1!, nnu: NNU__nu2): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar2Var0(nu: NU__u2!, nnu: NNU__nu0): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar2Var1(nu: NU__u2!, nnu: NNU__nu1): U @http(url: "http://localhost/users/{{args.nu.u}}")
-  testVar2Var2(nu: NU__u2!, nnu: NNU__nu2): U @http(url: "http://localhost/users/{{args.nu.u}}")
+  testVar0Var0(nu: NU__u0!, nnu: NNU__nu0): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar0Var1(nu: NU__u0!, nnu: NNU__nu1): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar0Var2(nu: NU__u0!, nnu: NNU__nu2): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar1Var0(nu: NU__u1!, nnu: NNU__nu0): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar1Var1(nu: NU__u1!, nnu: NNU__nu1): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar1Var2(nu: NU__u1!, nnu: NNU__nu2): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar2Var0(nu: NU__u2!, nnu: NNU__nu0): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar2Var1(nu: NU__u2!, nnu: NNU__nu1): U @http(url: "http://localhost/users/{{.args.nu.u}}")
+  testVar2Var2(nu: NU__u2!, nnu: NNU__nu2): U @http(url: "http://localhost/users/{{.args.nu.u}}")
 }
 
 type T1 {

tests/core/snapshots/yaml-union.md_merged.snap

@@ -30,9 +30,9 @@ type NU {
 }
 
 type Query {
-  testVar0(u: T1Input!): U @http(url: "http://localhost/users/{{args.u}}/")
-  testVar1(u: T2Input!): U @http(url: "http://localhost/users/{{args.u}}/")
-  testVar2(u: T3Input!): U @http(url: "http://localhost/users/{{args.u}}/")
+  testVar0(u: T1Input!): U @http(url: "http://localhost/users/{{.args.u}}/")
+  testVar1(u: T2Input!): U @http(url: "http://localhost/users/{{.args.u}}/")
+  testVar2(u: T3Input!): U @http(url: "http://localhost/users/{{.args.u}}/")
 }
 
 type T1 {

tests/core/spec.rs

@@ -16,10 +16,11 @@ use tailcall::core::async_graphql_hyper::{GraphQLBatchRequest, GraphQLRequest};
 use tailcall::core::blueprint::{Blueprint, BlueprintError};
 use tailcall::core::config::reader::ConfigReader;
 use tailcall::core::config::transformer::Required;
-use tailcall::core::config::{Config, ConfigModule, Source};
+use tailcall::core::config::{Config, ConfigModule, ConfigReaderContext, Source};
 use tailcall::core::http::handle_request;
 use tailcall::core::print_schema::print_schema;
 use tailcall::core::variance::Invariant;
+use tailcall::core::Mustache;
 use tailcall_prettier::Parser;
 use tailcall_valid::{Cause, Valid, ValidationError, Validator};
 
@@ -87,7 +88,7 @@ async fn is_sdl_error(spec: &ExecutionSpec, config_module: Valid<ConfigModule, S
     false
 }
 
-async fn check_identity(spec: &ExecutionSpec) {
+async fn check_identity(spec: &ExecutionSpec, reader_ctx: &ConfigReaderContext<'_>) {
     // TODO: we should probably figure out a way to do this for every test
     // but GraphQL identity checking is very hard, since a lot depends on the code
     // style the re-serializing check gives us some of the advantages of the
@@ -97,7 +98,8 @@ async fn check_identity(spec: &ExecutionSpec) {
     if spec.check_identity {
         for (source, content) in spec.server.iter() {
             if matches!(source, Source::GraphQL) {
-                let config = Config::from_source(source.to_owned(), content).unwrap();
+                let content = Mustache::parse(content).partial_render(reader_ctx);
+                let config = Config::from_source(source.to_owned(), &content).unwrap();
                 let actual = config.to_sdl();
 
                 // \r is added automatically in windows, it's safe to replace it with \n
@@ -190,11 +192,19 @@ async fn test_spec(spec: ExecutionSpec) {
 
     let mut runtime = runtime::create_runtime(mock_http_client.clone(), spec.env.clone(), None);
     runtime.file = Arc::new(File::new(spec.clone()));
+    let reader_ctx = ConfigReaderContext {
+        runtime: &runtime.clone(),
+        vars: &Default::default(),
+        headers: Default::default(),
+    };
+
     let reader = ConfigReader::init(runtime);
 
     // Resolve all configs
     let config_modules = join_all(spec.server.iter().map(|(source, content)| async {
-        let config = Config::from_source(source.to_owned(), content)?;
+        let content = Mustache::parse(content).partial_render(&reader_ctx);
+
+        let config = Config::from_source(source.to_owned(), &content)?;
 
         reader.resolve(config, spec.path.parent()).await
     }))
@@ -237,7 +247,7 @@ async fn test_spec(spec: ExecutionSpec) {
         .collect::<Result<Vec<_>, _>>()
         .unwrap();
 
-    check_identity(&spec).await;
+    check_identity(&spec, &reader_ctx).await;
 
     // client: Check if client spec matches snapshot
     if config_modules.len() == 1 {

tests/execution/test-eval-strict.md

@@ -0,0 +1,26 @@
+```graphql @config
+schema @server(port: 8080) @upstream(httpCache: 42, batch: {delay: 100}) {
+  query: Query
+}
+
+type Query {
+  post(id: Int!): [Post] @http(url: "http://jsonplaceholder.typicode.com/posts/{{.args.id}}")
+}
+
+type User {
+  id: Int!
+}
+
+type Post {
+  id: Int!
+  userId: Int!
+  foo: String @http(url: "http://jsonplaceholder.typicode.com/posts/{{.env.FOO}}")
+  user: User @http(url: "http://jsonplaceholder.typicode.com/users/{{.value.userId}}")
+}
+```
+
+```json @env
+{
+  "FOO": "foo"
+}
+```