Rename @pure to @readonly

Author: daniel-chambers

README.md

@@ -22,7 +22,7 @@ Any functions exported from `functions.ts` are made available as NDC functions/p
 Arguments to the function end up being field arguments in GraphQL and the return value is what the field will return when queried. Every function must return a value; `void`, `null` or `undefined` is not supported.
 
 ```typescript
-/** @pure */
+/** @readonly */
 export function hello(name: string, year: number): string {
   return `Hello ${name}, welcome to ${year}`
 }
@@ -130,16 +130,16 @@ These types are unsupported as function parameter types or return types for func
 
 
 ### Impure/pure functions
-If you write a function that performs a read-only operation, or is otherwise a pure function (no side-effects), you can mark it with the `@pure` JSDoc tag, and it will be exposed as an NDC function, which will ultimately show up as a GraphQL query field in Hasura.
+If you write a function that performs a read-only operation, you should mark it with the `@readonly` JSDoc tag, and it will be exposed as an NDC function, which will ultimately show up as a GraphQL query field in Hasura.
 
 ```typescript
-/** @pure */
+/** @readonly */
 export function add(x: number, y: number): number {
   return x + y;
 }
 ```
 
-Functions without the `@pure` JSDoc tag are exposed as NDC procedures, which will ultimately show up as a GraphQL mutation field in Hasura.
+Functions without the `@readonly` JSDoc tag are exposed as NDC procedures, which will ultimately show up as a GraphQL mutation field in Hasura.
 
 ## Deploying with `hasura3 connector create`
 

ndc-lambda-sdk/src/inference.ts

@@ -167,7 +167,7 @@ function deriveFunctionSchema(functionDeclaration: ts.FunctionDeclaration, conte
   const functionType = context.typeChecker.getTypeOfSymbolAtLocation(functionSymbol, functionDeclaration);
 
   const functionDescription = ts.displayPartsToString(functionSymbol.getDocumentationComment(context.typeChecker)).trim();
-  const markedPureInJsDoc = functionSymbol.getJsDocTags().find(e => e.name === "pure") !== undefined;
+  const markedReadonlyInJsDoc = functionSymbol.getJsDocTags().find(e => e.name === "readonly") !== undefined;
 
   const functionCallSig = functionType.getCallSignatures()[0] ?? throwError(`Function '${functionName}' didn't have a call signature`)
   const functionSchemaArguments: Result<schema.ArgumentDefinition[], string[]> = Result.traverseAndCollectErrors(functionCallSig.getParameters(), paramSymbol => {
@@ -190,7 +190,7 @@ function deriveFunctionSchema(functionDeclaration: ts.FunctionDeclaration, conte
   const functionDefinition = Result.collectErrors(functionSchemaArguments, returnTypeResult)
     .map(([functionSchemaArgs, returnType]) => ({
       description: functionDescription ? functionDescription : null,
-      ndcKind: markedPureInJsDoc ? schema.FunctionNdcKind.Function : schema.FunctionNdcKind.Procedure,
+      ndcKind: markedReadonlyInJsDoc ? schema.FunctionNdcKind.Function : schema.FunctionNdcKind.Procedure,
       arguments: functionSchemaArgs,
       resultType: returnType
     }));

ndc-lambda-sdk/test/inference/basic-inference/simple-types.ts

@@ -8,14 +8,14 @@ export function hello(): string {
 }
 
 /**
- * @pure
+ * @readonly
  */
 export function add(a: number, b: number): number {
   return a + b;
 }
 
 /**
- * @pure
+ * @readonly
  */
 export function isEven(x: bigint): boolean {
   return x % 2n === 0n;
@@ -26,7 +26,7 @@ export function dateTime(): Date {
 }
 
 /**
- * @pure
+ * @readonly
  */
 export function json(input: sdk.JSONValue): sdk.JSONValue {
   const jsonValue = input.value;

ndc-lambda-sdk/test/inference/external-dependencies/use-npm-package.ts

@@ -2,7 +2,7 @@
 import { emojify } from "node-emoji";
 
 /**
- * @pure
+ * @readonly
  */
 export function useImportedPackage(s: string): string {
   return emojify(`${s} :t-rex: :heart: NPM`);

yeoman-generator/src/app/templates/functions.ts

@@ -1,5 +1,5 @@
 /**
- * @pure Exposes the function as an NDC function (the function should only query data without making modifications)
+ * @readonly Exposes the function as an NDC function (the function should only query data without making modifications)
  */
 export function hello(name?: string) {
   return `hello ${name ?? "world"}`;