feat: add isReadOnly helper for functions

apps/docs-snippets/src/guide/contracts/is-function-readonly.test.ts

@@ -1,5 +1,3 @@
-import { bn } from 'fuels';
-
 import { DocSnippetProjectsEnum } from '../../../test/fixtures/forc-projects';
 import { createAndDeployContractFromProject } from '../../utils';
 
@@ -10,22 +8,14 @@ test('isReadOnly returns true for read-only functions', async () => {
   const contract = await createAndDeployContractFromProject(DocSnippetProjectsEnum.COUNTER);
 
   // #region is-function-readonly-1
-  const isReadOnly = contract.functions.get_count().isReadOnly();
-
-  expect(isReadOnly).toBe(true);
+  const isReadOnly = contract.functions.get_count.isReadOnly();
 
   if (isReadOnly) {
     await contract.functions.get_count().get();
   } else {
     await contract.functions.get_count().call();
   }
   // #endregion is-function-readonly-1
-});
 
-test('isReadOnly returns false for functions containing write operations', async () => {
-  const contract = await createAndDeployContractFromProject(DocSnippetProjectsEnum.COUNTER);
-
-  const isReadOnly = contract.functions.increment_count(bn(1)).isReadOnly();
-
-  expect(isReadOnly).toBe(false);
+  expect(isReadOnly).toBe(true);
 });

packages/abi-coder/src/FunctionFragment.ts

@@ -210,4 +210,14 @@ export class FunctionFragment<
 
     return coder.decode(bytes, 0) as [DecodedValue | undefined, number];
   }
+
+  /**
+   * Checks if the function is read-only i.e. it only reads from storage, does not write to it.
+   *
+   * @returns True if the function is read-only, false otherwise.
+   */
+  isReadOnly() {
+    const storageAttribute = this.attributes.find((attr) => attr.name === 'storage');
+    return !storageAttribute?.arguments.includes('write');
+  }
 }

packages/fuel-gauge/src/is-function-readonly.test.ts

@@ -0,0 +1,22 @@
+import { FuelGaugeProjectsEnum } from '../test/fixtures';
+
+import { getSetupContract } from './utils';
+
+/**
+ * @group node
+ */
+test('isReadOnly returns true for a read-only function', async () => {
+  const contract = await getSetupContract(FuelGaugeProjectsEnum.STORAGE_TEST_CONTRACT)();
+
+  const isReadOnly = contract.functions.counter.isReadOnly();
+
+  expect(isReadOnly).toBe(true);
+});
+
+test('isReadOnly returns false for a function containing write operations', async () => {
+  const contract = await getSetupContract(FuelGaugeProjectsEnum.STORAGE_TEST_CONTRACT)();
+
+  const isReadOnly = contract.functions.increment_counter.isReadOnly();
+
+  expect(isReadOnly).toBe(false);
+});

packages/program/src/contract.ts

@@ -6,7 +6,7 @@ import type { AbstractAddress, AbstractContract, BytesLike } from '@fuel-ts/inte
 
 import { FunctionInvocationScope } from './functions/invocation-scope';
 import { MultiCallInvocationScope } from './functions/multicall-scope';
-import type { InvokeFunctions } from './types';
+import type { InvokeFunction, InvokeFunctions } from './types';
 
 /**
  * `Contract` provides a way to interact with the contract program type.
@@ -89,7 +89,17 @@ export default class Contract implements AbstractContract {
    * @returns A function that creates a FunctionInvocationScope.
    */
   buildFunction(func: FunctionFragment) {
-    return (...args: Array<unknown>) => new FunctionInvocationScope(this, func, args);
+    return (() => {
+      const funcInvocationScopeCreator = (...args: Array<unknown>) =>
+        new FunctionInvocationScope(this, func, args);
+
+      Object.defineProperty(funcInvocationScopeCreator, 'isReadOnly', {
+        value: () => func.isReadOnly(),
+        writable: false,
+      });
+
+      return funcInvocationScopeCreator;
+    })() as InvokeFunction;
   }
 
   /**

packages/program/src/functions/invocation-scope.ts

@@ -99,14 +99,4 @@ export class FunctionInvocationScope<
 
     return this;
   }
-
-  /**
-   * Checks if the function is read-only i.e. it only reads from storage, does not write to it.
-   *
-   * @returns True if the function is read-only, false otherwise.
-   */
-  isReadOnly(): boolean {
-    const storageAttribute = this.func.attributes.find((attr) => attr.name === 'storage');
-    return !storageAttribute?.arguments.includes('write');
-  }
 }

packages/program/src/types.ts

@@ -64,9 +64,10 @@ export type CallConfig<T = unknown> = {
  * @template TReturn - Type of the function's return value.
  */
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
-export type InvokeFunction<TArgs extends Array<any> = Array<any>, TReturn = any> = (
-  ...args: TArgs
-) => FunctionInvocationScope<TArgs, TReturn>;
+export interface InvokeFunction<TArgs extends Array<any> = Array<any>, TReturn = any> {
+  (...args: TArgs): FunctionInvocationScope<TArgs, TReturn>;
+  isReadOnly: () => boolean;
+}
 
 /**
  * Represents a collection of functions that can be invoked.