Improve code generation (#204)

* single objects lookup

* generate seperate files

* config to disable static field generation

* add server setup docs

* make config.generateStaticFields optional

for backwards compatability

* support single file generation with .swift output

* make standard out just be the single file again

---------

Co-authored-by: Matic Zavadlal <matic.zavadlal@gmail.com>

Author: yonaskolb

.gitignore

@@ -1,6 +1,5 @@
 .DS_Store
 *.log*
-.env*
 
 # Swift
 

Sources/SwiftGraphQLCLI/main.swift

@@ -112,10 +112,18 @@ struct SwiftGraphQLCLI: ParsableCommand {
 
         let scalars = ScalarMap(scalars: config.scalars)
         let generator = GraphQLCodegen(scalars: scalars)
-        let code: String
-        
+        let files: [GeneratedFile]
+
+        // If the output is a Swift file generate a single file, otherwise multiple files in that directory
+        // If there's no output generate a single file as well as it will be printed to standard out
+        let singleFileOutput = output?.hasSuffix(".swift") ?? true
+
         do {
-            code = try generator.generate(schema: schema)
+            files = try generator.generate(
+                schema: schema,
+                generateStaticFields: config.generateStaticFields != false,
+                singleFile: singleFileOutput
+            )
             generateCodeSpinner.success("API generated successfully!")
         } catch CodegenError.formatting(let err) {
             generateCodeSpinner.error(err.localizedDescription)
@@ -131,9 +139,21 @@ struct SwiftGraphQLCLI: ParsableCommand {
 
         // Write to target file or stdout.
         if let outputPath = output {
-            try Folder.current.createFile(at: outputPath).write(code)
+            if singleFileOutput, let file = files.first {
+                // The generator returns a single file if asked to
+                try Folder.current.createFile(at: outputPath).write(file.contents)
+            } else {
+                // Clear the directory, in case some files were removed
+                try? Folder.current.subfolder(at: outputPath).delete()
+                for file in files {
+                    try Folder.current.createFile(at: "\(outputPath)/\(file.name).swift").write(file.contents)
+                }
+            }
         } else {
-            FileHandle.standardOutput.write(code.data(using: .utf8)!)
+            for file in files {
+                // this should always be one file anyway
+                FileHandle.standardOutput.write(file.contents.data(using: .utf8)!)
+            }
         }
 
         let analyzeSchemaSpinner = Spinner(.dots, "Analyzing Schema")
@@ -174,11 +194,15 @@ struct Config: Codable, Equatable {
     /// Key-Value dictionary of scalar mappings.
     let scalars: [String: String]
 
+    /// Whether to generate static lookups for object fields
+    var generateStaticFields: Bool?
+
     // MARK: - Initializers
 
     /// Creates an empty configuration instance.
     init() {
         self.scalars = [:]
+        self.generateStaticFields = true
     }
 
     /// Tries to decode the configuration from a string.

Sources/SwiftGraphQLCodegen/Generator.swift

@@ -14,79 +14,102 @@ public struct GraphQLCodegen {
     }
 
     // MARK: - Methods
-
-    /// Generates a SwiftGraphQL Selection File (i.e. the code that tells how to define selections).
-    public func generate(schema: Schema) throws -> String {
+    
+    /// Generates Swift files for the graph selections
+    /// - Parameters:
+    ///   - schema: The GraphQL schema
+    ///   - generateStaticFields: Whether to generate static selections for fields on objects
+    ///   - singleFile: Whether to return all the swift code in a single file
+    /// - Returns: A list of generated files
+    public func generate(schema: Schema, generateStaticFields: Bool, singleFile: Bool = false) throws -> [GeneratedFile] {
         let context = Context(schema: schema, scalars: self.scalars)
 
         let subscription = schema.operations.first { $0.isSubscription }?.type.name
-        
-        // Code Parts
+        let objects = schema.objects
         let operations = schema.operations.map { $0.declaration() }
-        let objectDefinitions = try schema.objects.map { object in
-            try object.declaration(
-                objects: schema.objects,
-                context: context,
-                alias: object.name != subscription
-            )
-        }
-        
-        let staticFieldSelection = try schema.objects.map { object in
-            try object.statics(context: context)
-        }
-        
-        let interfaceDefinitions = try schema.interfaces.map {
-            try $0.declaration(objects: schema.objects, context: context)
-        }
-        
-        let unionDefinitions = try schema.unions.map {
-            try $0.declaration(objects: schema.objects, context: context)
-        }
-        
-        let enumDefinitions = schema.enums.map { $0.declaration }
-        
-        let inputObjectDefinitions = try schema.inputObjects.map {
-            try $0.declaration(context: context)
-        }
-        
-        // API
-        let code = """
+
+        var files: [GeneratedFile] = []
+
+        let header = """
         // This file was auto-generated using maticzav/swift-graphql. DO NOT EDIT MANUALLY!
         import Foundation
         import GraphQL
         import SwiftGraphQL
+        """
 
-        // MARK: - Operations
+        let graphContents = """
         public enum Operations {}
         \(operations.lines)
 
-        // MARK: - Objects
         public enum Objects {}
-        \(objectDefinitions.lines)
-        \(staticFieldSelection.lines)
 
-        // MARK: - Interfaces
         public enum Interfaces {}
-        \(interfaceDefinitions.lines)
 
-        // MARK: - Unions
         public enum Unions {}
-        \(unionDefinitions.lines)
 
-        // MARK: - Enums
         public enum Enums {}
-        \(enumDefinitions.lines)
 
-        // MARK: - Input Objects
-        
         /// Utility pointer to InputObjects.
         public typealias Inputs = InputObjects
         
         public enum InputObjects {}
-        \(inputObjectDefinitions.lines)
         """
 
-        let formatted = try code.format()
-        return formatted
+        func addFile(name: String, contents: String) throws {
+            let fileContents: String
+            if singleFile {
+                fileContents = "\n// MARK: \(name)\n\(contents)"
+            } else {
+                fileContents = "\(header)\n\n\(contents)"
+            }
+            let file = GeneratedFile(name: name, contents: try fileContents.format())
+            files.append(file)
+        }
+
+        try addFile(name: "Graph", contents: graphContents)
+        for object in objects {
+            var contents = try object.declaration(
+                objects: objects,
+                context: context,
+                alias: object.name != subscription
+            )
+
+            if generateStaticFields {
+                let staticFieldSelection = try object.statics(context: context)
+                contents += "\n\n\(staticFieldSelection)"
+            }
+            try addFile(name: "Objects/\(object.name)", contents: contents)
+        }
+
+        for object in schema.inputObjects {
+            let contents = try object.declaration(context: context)
+            try addFile(name: "InputObjects/\(object.name)", contents: contents)
+        }
+
+        for enumSchema in schema.enums {
+            try addFile(name: "Enums/\(enumSchema.name)", contents: enumSchema.declaration)
+        }
+
+        for interface in schema.interfaces {
+            let contents = try interface.declaration(objects: objects, context: context)
+            try addFile(name: "Interfaces/\(interface.name)", contents: contents)
+        }
+
+        for union in schema.unions {
+            let contents = try union.declaration(objects: objects, context: context)
+            try addFile(name: "Unions/\(union.name)", contents: contents)
+        }
+
+        if singleFile {
+            let fileContent = "\(header)\n\n\(files.map(\.contents).joined(separator: "\n\n"))"
+            files = [GeneratedFile(name: "Graph", contents: fileContent)]
+        }
+
+        return files
     }
 }
+
+public struct GeneratedFile {
+    public let name: String
+    public let contents: String
+}

examples/thesocialnetwork/README.md

@@ -7,12 +7,26 @@ A sample server for a social network that
 - uses subscriptions,
 - lets users write to a shared feed.
 
+```bash
+# Start Server
+yarn start
+
+# Generate Prisma Client
+yarn prisma generate
+
+# Generate TypeGen
+yarn generate
+```
+
+
 ### Development Setup
 
 Start local Postgres database using Docker Compose.
 
 ```bash
+# Start DB in the background
 docker-compose up -d
 
-export DATABASE_URL="postgresql://prisma:prisma@localhost:5432/prisma"
+# Setup Environment variables
+cp .env.example .env
 ```

examples/thesocialnetwork/server/.env.example

@@ -0,0 +1,6 @@
+AWS_S3_BUCKET="thesocialnetwork-images"
+AWS_ACCESS_KEY_ID="AKIA3JJIBRRXWTIC7"
+AWS_SECRET_ACCESS_KEY="puU+kTKu288s+K9HpcbPGIrX79TItKly"
+
+DATABASE_URL="postgresql://prisma:prisma@localhost:5432/prisma"
+