Add shape validation for request variable

Author: andrewmcgivery

apollo-federation/src/sources/connect/validation/expression.rs

@@ -3,6 +3,7 @@
 
 use std::ops::Range;
 use std::str::FromStr;
+use std::sync::LazyLock;
 
 use apollo_compiler::collections::IndexMap;
 use apollo_compiler::parser::LineColumn;
@@ -24,6 +25,17 @@ use crate::sources::connect::validation::coordinates::ConnectDirectiveCoordinate
 use crate::sources::connect::validation::graphql::GraphQLString;
 use crate::sources::connect::validation::graphql::SchemaInfo;
 
+static REQUEST_SHAPE: LazyLock<Shape> = LazyLock::new(|| {
+    Shape::record(
+        [(
+            "headers".to_string(),
+            Shape::dict(Shape::list(Shape::string([]), []), []),
+        )]
+        .into(),
+        [],
+    )
+});
+
 /// Details about the available variables and shapes for the current expression.
 /// These should be consistent for all pieces of a connector in the request phase.
 pub(super) struct Context<'schema> {
@@ -53,7 +65,7 @@ impl<'schema> Context<'schema> {
                     (Namespace::Args, shape_for_arguments(field_def)),
                     (Namespace::Config, Shape::unknown([])),
                     (Namespace::Context, Shape::unknown([])),
-                    (Namespace::Request, Shape::unknown([])),
+                    (Namespace::Request, REQUEST_SHAPE.clone()),
                 ]
                 .into_iter()
                 .collect();
@@ -75,7 +87,7 @@ impl<'schema> Context<'schema> {
                     (Namespace::Batch, Shape::list(Shape::from(type_def), [])),
                     (Namespace::Config, Shape::unknown([])),
                     (Namespace::Context, Shape::unknown([])),
-                    (Namespace::Request, Shape::unknown([])),
+                    (Namespace::Request, REQUEST_SHAPE.clone()),
                 ]
                 .into_iter()
                 .collect();
@@ -99,6 +111,7 @@ impl<'schema> Context<'schema> {
         let var_lookup: IndexMap<Namespace, Shape> = [
             (Namespace::Config, Shape::unknown([])),
             (Namespace::Context, Shape::unknown([])),
+            (Namespace::Request, REQUEST_SHAPE.clone()),
         ]
         .into_iter()
         .collect();

apollo-federation/src/sources/connect/validation/snapshots/validation_tests@headers__invalid_namespace_in_header_variables.graphql.snap

@@ -6,21 +6,21 @@ input_file: apollo-federation/src/sources/connect/validation/test_data/headers/i
 [
     Message {
         code: InvalidHeader,
-        message: "In `@source(http.headers:)`: unknown variable `$foo`, must be one of $config, $context",
+        message: "In `@source(http.headers:)`: unknown variable `$foo`, must be one of $config, $context, $request",
         locations: [
             11:49..11:53,
         ],
     },
     Message {
         code: InvalidHeader,
-        message: "In `@source(http.headers:)`: $this is not valid here, must be one of $config, $context",
+        message: "In `@source(http.headers:)`: $this is not valid here, must be one of $config, $context, $request",
         locations: [
             12:62..12:67,
         ],
     },
     Message {
         code: InvalidHeader,
-        message: "In `@source(http.headers:)`: `config.bar` must start with one of $config, $context",
+        message: "In `@source(http.headers:)`: `config.bar` must start with one of $config, $context, $request",
         locations: [
             13:56..13:62,
         ],

apollo-federation/src/sources/connect/validation/snapshots/validation_tests@request_headers.graphql.snap

@@ -0,0 +1,31 @@
+---
+source: apollo-federation/src/sources/connect/validation/mod.rs
+expression: "format!(\"{:#?}\", result.errors)"
+input_file: apollo-federation/src/sources/connect/validation/test_data/request_headers.graphql
+---
+[
+    Message {
+        code: InvalidHeader,
+        message: "In `@source(http.headers:)`: array values aren't valid here",
+        locations: [
+            5:101..5:111,
+            5:101..5:111,
+        ],
+    },
+    Message {
+        code: InvalidHeader,
+        message: "In `@connect(http.headers:)` on `Query.failOnArray`: array values aren't valid here",
+        locations: [
+            28:68..28:78,
+            28:68..28:78,
+        ],
+    },
+    Message {
+        code: InvalidUrl,
+        message: "In `GET` in `@connect(http:)` on `Query.failOnArray`: array values aren't valid here",
+        locations: [
+            27:61..27:71,
+            27:61..27:71,
+        ],
+    },
+]

apollo-federation/src/sources/connect/validation/test_data/request_headers.graphql

@@ -0,0 +1,32 @@
+extend schema
+  @link(url: "https://specs.apollo.dev/connect/v0.1", import: ["@connect", "@source"])
+  @source(
+    name: "invalid_api"
+    http: { baseURL: "http://127.0.0.1", headers: [{ name: "x-my-header", value: "{$request.headers.someheader}" }] }
+  )
+  @source(
+    name: "awesome_api"
+    http: {
+      baseURL: "http://127.0.0.1"
+      headers: [{ name: "x-my-header", value: "{$request.headers.someheader->first}" }]
+    }
+  )
+
+type Query {
+  pass: [String!]!
+    @connect(
+      http: {
+        GET: "http://127.0.0.1/?something={$request.headers.someheader->first}"
+        headers: [{ name: "x-my-header", value: "{$request.headers.someheader->first}" }]
+      }
+      selection: "$"
+    )
+  failOnArray: [String!]!
+    @connect(
+      http: {
+        GET: "http://127.0.0.1/?something={$request.headers.someheader}"
+        headers: [{ name: "x-my-header", value: "{$request.headers.someheader}" }]
+      }
+      selection: "$"
+    )
+}