Add support for Relay projects without artifactDirectory (#33918)

* update plugin

* Update the test

* remove dbg

* Use pages_dir in Relay

* copy edits

* cargo test

Co-authored-by: JJ Kasper <jj@jjsweb.site>

packages/next-swc/crates/core/src/lib.rs

@@ -112,7 +112,7 @@ pub fn custom_before_pass(
     #[cfg(not(target_arch = "wasm32"))]
     let relay_plugin = {
         if let Some(config) = &opts.relay {
-            Either::Left(relay::relay(config, file.name.clone()))
+            Either::Left(relay::relay(config, file.name.clone(), opts.pages_dir.clone()))
         } else {
             Either::Right(noop())
         }

packages/next-swc/crates/core/src/relay.rs

@@ -24,6 +24,7 @@ impl Default for RelayLanguageConfig {
 
 struct Relay<'a> {
     root_dir: PathBuf,
+    pages_dir: PathBuf,
     file_name: FileName,
     config: &'a Config,
 }
@@ -85,36 +86,44 @@ impl<'a> Fold for Relay<'a> {
 #[derive(Debug)]
 enum BuildRequirePathError {
     FileNameNotReal,
-    ArtifactDirectoryExpected,
+    ArtifactDirectoryExpected { file_name: String },
 }
 
-fn path_for_artifact(
-    root_dir: &Path,
-    config: &Config,
-    definition_name: &str,
-) -> Result<PathBuf, BuildRequirePathError> {
-    let filename = match &config.language {
-        RelayLanguageConfig::Flow => format!("{}.graphql.js", definition_name),
-        RelayLanguageConfig::TypeScript => {
-            format!("{}.graphql.ts", definition_name)
-        }
-    };
+impl<'a> Relay<'a> {
+    fn path_for_artifact(
+        &self,
+        real_file_name: &Path,
+        definition_name: &str,
+    ) -> Result<PathBuf, BuildRequirePathError> {
+        let filename = match &self.config.language {
+            RelayLanguageConfig::Flow => format!("{}.graphql.js", definition_name),
+            RelayLanguageConfig::TypeScript => {
+                format!("{}.graphql.ts", definition_name)
+            }
+        };
 
-    if let Some(artifact_directory) = &config.artifact_directory {
-        Ok(root_dir.join(artifact_directory).join(filename))
-    } else {
-        Err(BuildRequirePathError::ArtifactDirectoryExpected)
+        if let Some(artifact_directory) = &self.config.artifact_directory {
+            Ok(self.root_dir.join(artifact_directory).join(filename))
+        } else if real_file_name.starts_with(&self.pages_dir) {
+            Err(BuildRequirePathError::ArtifactDirectoryExpected {
+                file_name: real_file_name.display().to_string(),
+            })
+        } else {
+            Ok(real_file_name
+                .parent()
+                .unwrap()
+                .join("__generated__")
+                .join(filename))
+        }
     }
-}
 
-impl<'a> Relay<'a> {
     fn build_require_path(
         &mut self,
         operation_name: &str,
     ) -> Result<PathBuf, BuildRequirePathError> {
         match &self.file_name {
-            FileName::Real(_real_file_name) => {
-                path_for_artifact(&self.root_dir, self.config, operation_name)
+            FileName::Real(real_file_name) => {
+                self.path_for_artifact(real_file_name, operation_name)
             }
             _ => Err(BuildRequirePathError::FileNameNotReal),
         }
@@ -140,10 +149,14 @@ impl<'a> Relay<'a> {
                                                                    file. This is likely a bug and \
                                                                    should be reported to Next.js"
                             .to_string(),
-                        BuildRequirePathError::ArtifactDirectoryExpected => {
-                            "The `artifactDirectory` is expected to be set in the Relay config \
-                             file to work correctly with Next.js."
-                                .to_string()
+                        BuildRequirePathError::ArtifactDirectoryExpected { file_name } => {
+                            format!(
+                                "The generated file for `{}` will be created in `pages` \
+                                 directory, which will break production builds. Try moving the \
+                                 file outside of `pages` or set the `artifactDirectory` in the \
+                                 Relay config file.",
+                                file_name
+                            )
                         }
                     };
 
@@ -161,10 +174,15 @@ impl<'a> Relay<'a> {
     }
 }
 
-pub fn relay<'a>(config: &'a Config, file_name: FileName) -> impl Fold + '_ {
+pub fn relay<'a>(
+    config: &'a Config,
+    file_name: FileName,
+    pages_dir: Option<PathBuf>,
+) -> impl Fold + '_ {
     Relay {
         root_dir: std::env::current_dir().unwrap(),
         file_name,
+        pages_dir: pages_dir.unwrap_or_else(|| panic!("pages_dir is expected.")),
         config,
     }
 }

packages/next-swc/crates/core/tests/fixture.rs

@@ -160,7 +160,13 @@ fn relay_no_artifact_dir_fixture(input: PathBuf) {
     };
     test_fixture(
         syntax(),
-        &|_tr| relay(&config, FileName::Real(PathBuf::from("input.tsx"))),
+        &|_tr| {
+            relay(
+                &config,
+                FileName::Real(PathBuf::from("input.tsx")),
+                Some(PathBuf::from("src/pages")),
+            )
+        },
         &input,
         &output,
     );

test/integration/relay-graphql-swc-single-project/pages/index.tsx

@@ -2,13 +2,13 @@ import {
   Environment,
   FetchFunction,
   fetchQuery,
-  graphql,
   Network,
   RecordSource,
   Store,
 } from 'relay-runtime'
 import { GetServerSideProps } from 'next'
-import { pagesQuery } from '../__generated__/pagesQuery.graphql'
+import { pagesQuery as pagesQueryType } from '../queries/__generated__/pagesQuery.graphql'
+import pagesQuery from '../queries/pagesQuery'
 
 type Props = { greeting: string }
 
@@ -41,13 +41,9 @@ export const getServerSideProps: GetServerSideProps = async ({ req }) => {
     network: Network.create(createGraphQLFetcher(req.headers.host)),
   })
 
-  const result = await fetchQuery<pagesQuery>(
+  const result = await fetchQuery<pagesQueryType>(
     environment,
-    graphql`
-      query pagesQuery {
-        greeting
-      }
-    `,
+    pagesQuery,
     {}
   ).toPromise()
 

test/integration/relay-graphql-swc-single-project/queries/pagesQuery.js

@@ -0,0 +1,7 @@
+import { graphql } from 'relay-runtime'
+
+export default graphql`
+  query pagesQuery {
+    greeting
+  }
+`

test/integration/relay-graphql-swc-single-project/relay.config.js

@@ -1,6 +1,5 @@
 module.exports = {
   src: './pages',
   schema: './schema.graphql',
-  artifactDirectory: './__generated__',
   language: 'typescript',
 }