feat: show default values of parameters in signature help (#1251)

Closes #1147 ### Summary of Changes Show default values of parameters in the signature help. Previously, it only showed whether a parameter was optional or not.
Safe-DS · Nov 1, 2024 · ff8fa13 · ff8fa13
1 parent 5913a54
commit ff8fa13
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Showing 2 changed files with 14 additions and 20 deletions.
diff --git a/packages/safe-ds-lang/src/language/lsp/safe-ds-signature-help-provider.ts b/packages/safe-ds-lang/src/language/lsp/safe-ds-signature-help-provider.ts
@@ -16,11 +16,10 @@ import type {
 } from 'vscode-languageserver';
 import { createMarkupContent } from '../documentation/safe-ds-comment-provider.js';
 import { isSdsAbstractCall, SdsCallable, SdsParameter } from '../generated/ast.js';
-import { getParameters, Parameter } from '../helpers/nodeProperties.js';
+import { getParameters } from '../helpers/nodeProperties.js';
 import { type SafeDsNodeMapper } from '../helpers/safe-ds-node-mapper.js';
 import type { SafeDsServices } from '../safe-ds-module.js';
 import { type SafeDsTypeComputer } from '../typing/safe-ds-type-computer.js';
-import { CallableType, NamedType } from '../typing/model.js';
 import { SignatureHelpProvider } from 'langium/lsp';
 
 export class SafeDsSignatureHelpProvider implements SignatureHelpProvider {
@@ -88,17 +87,11 @@ export class SafeDsSignatureHelpProvider implements SignatureHelpProvider {
     }
 
     private getLabel(callable: SdsCallable): string {
-        const type = this.typeComputer.computeType(callable);
-
-        if (type instanceof NamedType) {
-            return `${type.declaration.name}(${getParameters(callable)
-                .map((it) => this.getParameterLabel(it))
-                .join(', ')})`;
-        } else if (type instanceof CallableType && isNamed(callable)) {
-            return `${callable.name}${type}`;
-        } else {
-            return type.toString();
-        }
+        const name = isNamed(callable) ? callable.name : 'λ';
+        const parameters = `(${getParameters(callable)
+            .map((it) => this.getParameterLabel(it))
+            .join(', ')})`;
+        return `${name}${parameters}`;
     }
 
     private getParameterInformation = (parameter: SdsParameter) => {
@@ -108,9 +101,10 @@ export class SafeDsSignatureHelpProvider implements SignatureHelpProvider {
     };
 
     private getParameterLabel = (parameter: SdsParameter) => {
-        const optionality = Parameter.isOptional(parameter) ? '?' : '';
         const type = this.typeComputer.computeType(parameter);
-        return `${parameter.name}${optionality}: ${type}`;
+        const defaultValueCstNode = parameter.defaultValue?.$cstNode;
+        const defaultValue = defaultValueCstNode ? ` = ${defaultValueCstNode.text}` : '';
+        return `${parameter.name}: ${type}${defaultValue}`;
     };
 
     /* c8 ignore start */

diff --git a/packages/safe-ds-lang/tests/language/lsp/safe-ds-signature-help-provider.test.ts b/packages/safe-ds-lang/tests/language/lsp/safe-ds-signature-help-provider.test.ts
@@ -90,7 +90,7 @@ describe('SafeDsSignatureHelpProvider', async () => {
             `,
             expectedSignature: [
                 {
-                    label: 'A(p: Int) -> ()',
+                    label: 'A(p: Int)',
                     documentation: {
                         kind: 'markdown',
                         value: 'Lorem ipsum.',
@@ -144,7 +144,7 @@ describe('SafeDsSignatureHelpProvider', async () => {
             `,
             expectedSignature: [
                 {
-                    label: 'f(p: Int) -> ()',
+                    label: 'f(p: Int)',
                     documentation: {
                         kind: 'markdown',
                         value: 'Lorem ipsum.',
@@ -166,7 +166,7 @@ describe('SafeDsSignatureHelpProvider', async () => {
             `,
             expectedSignature: [
                 {
-                    label: '(p: Int) -> ()',
+                    label: 'λ(p: Int)',
                     documentation: undefined,
                     parameters: [
                         {
@@ -188,11 +188,11 @@ describe('SafeDsSignatureHelpProvider', async () => {
             `,
             expectedSignature: [
                 {
-                    label: 'f(p?: Int) -> ()',
+                    label: 'f(p: Int = 0)',
                     documentation: undefined,
                     parameters: [
                         {
-                            label: 'p?: Int',
+                            label: 'p: Int = 0',
                         },
                     ],
                 },