perf: add a few performance optimizations

src/ast.ts

@@ -1,4 +1,4 @@
-import genFn from "generate-function";
+import { genFn } from "./generate";
 import {
   type ArgumentNode,
   type ASTNode,
@@ -41,15 +41,15 @@ export interface JitFieldNode extends FieldNode {
    * @deprecated Use __internalShouldIncludePath instead
    * @see __internalShouldIncludePath
    */
-  __internalShouldInclude?: string;
+  __internalShouldInclude?: string[];
 
   // The shouldInclude logic is specific to the current path
   // This is because the same fieldNode can be reached from different paths
   // - for example, the same fragment used in two different places
   __internalShouldIncludePath?: {
     // Key is the stringified ObjectPath,
     // Value is the shouldInclude logic for that path
-    [path: string]: string;
+    [path: string]: string[];
   };
 }
 
@@ -96,7 +96,7 @@ function collectFieldsImpl(
   selectionSet: SelectionSetNode,
   fields: FieldsAndNodes,
   visitedFragmentNames: { [key: string]: boolean },
-  previousShouldInclude = "",
+  previousShouldInclude: string[] = [],
   parentResponsePath = ""
 ): FieldsAndNodes {
   for (const selection of selectionSet.selections) {
@@ -146,16 +146,16 @@ function collectFieldsImpl(
 
           fieldNode.__internalShouldIncludePath[currentPath] =
             joinShouldIncludeCompilations(
-              fieldNode.__internalShouldIncludePath?.[currentPath] ?? "",
+              fieldNode.__internalShouldIncludePath?.[currentPath] ?? [],
               previousShouldInclude,
-              compiledSkipInclude
+              [compiledSkipInclude]
             );
         } else {
           // @deprecated
           fieldNode.__internalShouldInclude = joinShouldIncludeCompilations(
-            fieldNode.__internalShouldInclude ?? "",
+            fieldNode.__internalShouldInclude ?? [],
             previousShouldInclude,
-            compiledSkipInclude
+            [compiledSkipInclude]
           );
         }
         /**
@@ -199,7 +199,7 @@ function collectFieldsImpl(
             // `should include`s from previous fragments
             previousShouldInclude,
             // current fragment's shouldInclude
-            compiledSkipInclude
+            [compiledSkipInclude]
           ),
           parentResponsePath
         );
@@ -237,7 +237,7 @@ function collectFieldsImpl(
             // `should include`s from previous fragments
             previousShouldInclude,
             // current fragment's shouldInclude
-            compiledSkipInclude
+            [compiledSkipInclude]
           ),
           parentResponsePath
         );
@@ -335,15 +335,15 @@ function augmentFieldNodeTree(
               joinShouldIncludeCompilations(
                 parentFieldNode.__internalShouldIncludePath?.[
                   parentResponsePath
-                ] ?? "",
-                jitFieldNode.__internalShouldIncludePath?.[currentPath] ?? ""
+                ] ?? [],
+                jitFieldNode.__internalShouldIncludePath?.[currentPath] ?? []
               );
           } else {
             // @deprecated
             jitFieldNode.__internalShouldInclude =
               joinShouldIncludeCompilations(
-                parentFieldNode.__internalShouldInclude ?? "",
-                jitFieldNode.__internalShouldInclude ?? ""
+                parentFieldNode.__internalShouldInclude ?? [],
+                jitFieldNode.__internalShouldInclude ?? []
               );
           }
         }
@@ -392,7 +392,7 @@ function augmentFieldNodeTree(
  *
  * @param compilations
  */
-function joinShouldIncludeCompilations(...compilations: string[]) {
+function joinShouldIncludeCompilations(...compilations: string[][]): string[] {
   // remove "true" since we are joining with '&&' as `true && X` = `X`
   // This prevents an explosion of `&& true` which could break
   // V8's internal size limit for string.
@@ -404,16 +404,16 @@ function joinShouldIncludeCompilations(...compilations: string[]) {
   // Failing to do this results in [RangeError: invalid array length]
   // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Invalid_array_length
 
-  // remove empty strings
-  let filteredCompilations = compilations.filter((it) => it);
+  const conditionsSet = new Set<string>();
+  for (const conditions of compilations) {
+    for (const condition of conditions) {
+      if (condition !== "true") {
+        conditionsSet.add(condition);
+      }
+    }
+  }
 
-  // Split conditions by && and flatten it
-  filteredCompilations = ([] as string[]).concat(
-    ...filteredCompilations.map((e) => e.split(" && ").map((it) => it.trim()))
-  );
-  // Deduplicate items
-  filteredCompilations = Array.from(new Set(filteredCompilations));
-  return filteredCompilations.join(" && ");
+  return Array.from(conditionsSet);
 }
 
 /**
@@ -427,8 +427,6 @@ function compileSkipInclude(
   compilationContext: CompilationContext,
   node: SelectionNode
 ): string {
-  const gen = genFn();
-
   const { skipValue, includeValue } = compileSkipIncludeDirectiveValues(
     compilationContext,
     node
@@ -446,16 +444,14 @@ function compileSkipInclude(
    * condition is true or the @include condition is false.
    */
   if (skipValue != null && includeValue != null) {
-    gen(`${skipValue} === false && ${includeValue} === true`);
+    return `${skipValue} === false && ${includeValue} === true`;
   } else if (skipValue != null) {
-    gen(`(${skipValue} === false)`);
+    return `(${skipValue} === false)`;
   } else if (includeValue != null) {
-    gen(`(${includeValue} === true)`);
+    return `(${includeValue} === true)`;
   } else {
-    gen(`true`);
+    return `true`;
   }
-
-  return gen.toString();
 }
 
 /**

src/execution.ts

@@ -1,6 +1,6 @@
 import { type TypedDocumentNode } from "@graphql-typed-document-node/core";
 import fastJson from "fast-json-stringify";
-import genFn from "generate-function";
+import { genFn } from "./generate";
 import {
   type ASTNode,
   type DocumentNode,
@@ -65,8 +65,10 @@ import {
   failToParseVariables
 } from "./variables.js";
 import { getGraphQLErrorOptions, getOperationRootType } from "./compat.js";
+import memoize from "lodash.memoize";
 
 const inspect = createInspect();
+const joinOriginPaths = memoize(joinOriginPathsImpl);
 
 export interface CompilerOptions {
   customJSONSerializer: boolean;
@@ -129,6 +131,7 @@ interface DeferredField {
   name: string;
   responsePath: ObjectPath;
   originPaths: string[];
+  originPathsFormatted: string;
   destinationPaths: string[];
   parentType: GraphQLObjectType;
   fieldName: string;
@@ -517,7 +520,7 @@ function compileDeferredField(
 ): string {
   const {
     name,
-    originPaths,
+    originPathsFormatted,
     destinationPaths,
     fieldNodes,
     fieldType,
@@ -562,7 +565,7 @@ function compileDeferredField(
     responsePath
   );
   const emptyError = createErrorObject(context, fieldNodes, responsePath, '""');
-  const resolverParentPath = originPaths.join(".");
+  const resolverParentPath = originPathsFormatted;
   const resolverCall = `${GLOBAL_EXECUTION_CONTEXT}.resolvers.${resolverName}(
           ${resolverParentPath},${topLevelArgs},${GLOBAL_CONTEXT_NAME}, ${executionInfo})`;
   const resultParentPath = destinationPaths.join(".");
@@ -661,7 +664,7 @@ function compileType(
   destinationPaths: string[],
   previousPath: ObjectPath
 ): string {
-  const sourcePath = originPaths.join(".");
+  const sourcePath = joinOriginPaths(originPaths);
   let body = `${sourcePath} == null ? `;
   let errorDestination;
   if (isNonNullType(type)) {
@@ -754,7 +757,7 @@ function compileLeafType(
     context.options.disableLeafSerialization &&
     (type instanceof GraphQLEnumType || isSpecifiedScalarType(type))
   ) {
-    body += `${originPaths.join(".")}`;
+    body += `${joinOriginPaths(originPaths)}`;
   } else {
     const serializerName = getSerializerName(type.name);
     context.serializers[serializerName] = getSerializer(
@@ -775,8 +778,8 @@ function compileLeafType(
       "message"
     )});}
     `);
-    body += `${GLOBAL_EXECUTION_CONTEXT}.serializers.${serializerName}(${GLOBAL_EXECUTION_CONTEXT}, ${originPaths.join(
-      "."
+    body += `${GLOBAL_EXECUTION_CONTEXT}.serializers.${serializerName}(${GLOBAL_EXECUTION_CONTEXT}, ${joinOriginPaths(
+      originPaths
     )}, ${serializerErrorHandler}, ${parentIndexes})`;
   }
   return body;
@@ -815,15 +818,17 @@ function compileObjectType(
     body(
       `!${GLOBAL_EXECUTION_CONTEXT}.isTypeOfs["${
         type.name
-      }IsTypeOf"](${originPaths.join(
-        "."
+      }IsTypeOf"](${joinOriginPaths(
+        originPaths
       )}) ? (${errorDestination}.push(${createErrorObject(
         context,
         fieldNodes,
         responsePath as any,
         `\`Expected value of type "${
           type.name
-        }" but got: $\{${GLOBAL_INSPECT_NAME}(${originPaths.join(".")})}.\``
+        }" but got: $\{${GLOBAL_INSPECT_NAME}(${joinOriginPaths(
+          originPaths
+        )})}.\``
       )}), null) :`
     );
   }
@@ -872,15 +877,32 @@ function compileObjectType(
       name
     );
 
-    const fieldCondition = context.options.useExperimentalPathBasedSkipInclude
-      ? fieldNodes
-          .map((it) => it.__internalShouldIncludePath?.[serializedResponsePath])
-          .filter((it) => it)
-          .join(" || ") || /* if(true) - default */ "true"
-      : fieldNodes
-          .map((it) => it.__internalShouldInclude)
-          .filter((it) => it)
-          .join(" || ") || /* if(true) - default */ "true";
+    const fieldConditionsList = (
+      context.options.useExperimentalPathBasedSkipInclude
+        ? fieldNodes.map(
+            (it) => it.__internalShouldIncludePath?.[serializedResponsePath]
+          )
+        : fieldNodes.map((it) => it.__internalShouldInclude)
+    ).filter(isNotNull);
+
+    let fieldCondition = fieldConditionsList
+      .map((it) => {
+        if (it.length > 0) {
+          return `(${it.join(" && ")})`;
+        }
+        // default: if there are no conditions, it means that the field
+        // is always included in the path
+        return "true";
+      })
+      .filter(isNotNull)
+      .join(" || ");
+
+    // if it's an empty string, it means that the field is always included
+    if (!fieldCondition) {
+      // if there are no conditions, it means that the field
+      // is always included in the path
+      fieldCondition = "true";
+    }
 
     body(`
       (
@@ -907,6 +929,7 @@ function compileObjectType(
         name,
         responsePath: addPath(responsePath, name),
         originPaths,
+        originPathsFormatted: joinOriginPaths(originPaths),
         destinationPaths,
         parentType: type,
         fieldName: field.name,
@@ -1046,8 +1069,8 @@ function compileAbstractType(
       return null;
     }
   })(
-    ${GLOBAL_EXECUTION_CONTEXT}.typeResolvers.${typeResolverName}(${originPaths.join(
-      "."
+    ${GLOBAL_EXECUTION_CONTEXT}.typeResolvers.${typeResolverName}(${joinOriginPaths(
+      originPaths
     )},
     ${GLOBAL_CONTEXT_NAME},
     ${getExecutionInfo(
@@ -1916,3 +1939,11 @@ function mapAsyncIterator<T, U, R = undefined>(
     }
   };
 }
+
+function joinOriginPathsImpl(originPaths: string[]) {
+  return originPaths.join(".");
+}
+
+function isNotNull<T>(it: T): it is Exclude<T, null | undefined> {
+  return it != null;
+}

src/generate.ts

@@ -0,0 +1,12 @@
+export function genFn() {
+  let body = "";
+
+  function add(str: string) {
+    body += str + "\n";
+    return add;
+  }
+
+  add.toString = () => body;
+
+  return add;
+}

src/resolve-info.ts

@@ -1,4 +1,4 @@
-import genFn from "generate-function";
+import { genFn } from "./generate";
 import {
   doTypesOverlap,
   type FieldNode,

src/variables.ts

@@ -1,4 +1,4 @@
-import genFn from "generate-function";
+import { genFn } from "./generate";
 import {
   GraphQLBoolean,
   GraphQLError,