Detect default values on destructured parameters

Resolves #2430

CHANGELOG.md

@@ -20,6 +20,7 @@
 -   TypeDoc now inherits `typedocOptions` fields from extended tsconfig files, #2334.
 -   Methods which return function types no longer have duplicated comments, #2336.
 -   Comments on function-like type aliases will now show up under the type alias, rather than nested within the type declaration, #2372.
+-   Improved detection of default values for parameters with destructured values, #2430.
 -   Fix crash when converting some complicated union/intersection types, #2451.
 -   Navigation triangle markers should no longer display on a separate line with some font settings, #2457.
 -   `@group` and `@category` organization is now applied later to allow inherited comments to create groups/categories, #2459.

src/lib/converter/factories/signature.ts

@@ -214,6 +214,7 @@ function convertParameters(
         }
 
         paramRefl.setFlag(ReflectionFlag.Rest, isRest);
+        checkForDestructuredParameterDefaults(paramRefl, parameterNodes?.[i]);
         return paramRefl;
     });
 }
@@ -261,10 +262,31 @@ export function convertParameterNodes(
                 : !!param.typeExpression &&
                       ts.isJSDocVariadicType(param.typeExpression.type),
         );
+        checkForDestructuredParameterDefaults(paramRefl, param);
         return paramRefl;
     });
 }
 
+function checkForDestructuredParameterDefaults(
+    param: ParameterReflection,
+    decl: ts.ParameterDeclaration | ts.JSDocParameterTag | undefined,
+) {
+    if (!decl || !ts.isParameter(decl)) return;
+    if (param.name !== "__namedParameters") return;
+    if (!ts.isObjectBindingPattern(decl.name)) return;
+    if (param.type?.type !== "reflection") return;
+
+    for (const child of param.type.declaration.children || []) {
+        const tsChild = decl.name.elements.find(
+            (el) => (el.propertyName || el.name).getText() === child.name,
+        );
+
+        if (tsChild) {
+            child.defaultValue = convertDefaultValue(tsChild);
+        }
+    }
+}
+
 function convertTypeParameters(
     context: Context,
     parent: Reflection,

src/test/converter/variables/specs.json

@@ -687,7 +687,8 @@
                                 "name": "boolean"
                               }
                             ]
-                          }
+                          },
+                          "defaultValue": "false"
                         },
                         {
                           "id": 21,
@@ -716,7 +717,8 @@
                                 ]
                               }
                             ]
-                          }
+                          },
+                          "defaultValue": "..."
                         },
                         {
                           "id": 20,
@@ -736,7 +738,8 @@
                                 "name": "string"
                               }
                             ]
-                          }
+                          },
+                          "defaultValue": "\"\""
                         }
                       ],
                       "groups": [

src/test/converter/variables/specs.nodoc.json

@@ -327,7 +327,8 @@
                                 "name": "boolean"
                               }
                             ]
-                          }
+                          },
+                          "defaultValue": "false"
                         },
                         {
                           "id": 21,
@@ -356,7 +357,8 @@
                                 ]
                               }
                             ]
-                          }
+                          },
+                          "defaultValue": "..."
                         },
                         {
                           "id": 20,
@@ -376,7 +378,8 @@
                                 "name": "string"
                               }
                             ]
-                          }
+                          },
+                          "defaultValue": "\"\""
                         }
                       ],
                       "groups": [

src/test/converter2/issues/gh2430.js

@@ -0,0 +1,11 @@
+/**
+ * @param {object} props
+ * @param {any} props.value Value
+ * @param {any} props.trueValue True default
+ * @param {any} props.falseValue False default
+ */
+export const Checkbox = ({
+    value,
+    trueValue = true,
+    falseValue: renamed = false,
+}) => {};

src/test/issues.c2.test.ts

@@ -1276,6 +1276,25 @@ describe("Issue Tests", () => {
         );
     });
 
+    it("Handles destructured object parameter defaults, #2430", () => {
+        const project = convert();
+        const Checkbox = querySig(project, "Checkbox");
+        equal(Checkbox.parameters?.length, 1);
+        equal(Checkbox.parameters[0].name, "props");
+        const type = Checkbox.parameters[0].type;
+        equal(type?.type, "reflection");
+        equal(type.declaration.children?.map((c) => c.name), [
+            "falseValue",
+            "trueValue",
+            "value",
+        ]);
+        equal(type.declaration.children?.map((c) => c.defaultValue), [
+            "false",
+            "true",
+            undefined,
+        ]);
+    });
+
     it("Handles function-namespaces created with Object.assign #2436", () => {
         const project = convert();
         equal(query(project, "bug").kind, ReflectionKind.Function);