feature: implement optional function param

mistlog · Mar 12, 2021 · 8f9cfb1 · 8f9cfb1
1 parent 899a647
commit 8f9cfb1
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Showing 8 changed files with 94 additions and 1 deletion.
diff --git a/src/generator/generator.ts b/src/generator/generator.ts
@@ -194,6 +194,9 @@ function tsFunctionParams(params: IFunctionTypeParam[]) {
         const identifier = Identifier(each.name);
         const param = each.rest ? t.restElement(identifier) : identifier;
         param.typeAnnotation = t.tsTypeAnnotation(TSType(each.type));
+        if (each.optional) {
+            param["optional"] = true
+        }
         return param;
     });
 }

diff --git a/src/parser/function/function.tsx b/src/parser/function/function.tsx
@@ -69,10 +69,11 @@ export interface IFunctionTypeParam {
     name: IIdentifier
     type: ITypeExpression
     rest?: boolean
+    optional?: boolean
 }
 
 export function FunctionTypeParam() {
-    const action = ({ name, type, rest }): IFunctionTypeParam => {
+    const action = ({ name, type, rest, optional }): IFunctionTypeParam => {
         const param: IFunctionTypeParam = {
             kind: "FunctionTypeParam",
             name,
@@ -83,6 +84,10 @@ export function FunctionTypeParam() {
             param.rest = true
         }
 
+        if (optional) {
+            param.optional = true
+        }
+
         return param
     }
 
@@ -93,6 +98,9 @@ export function FunctionTypeParam() {
                 <text>...</text>
             </opt>
             <Identifier label="name" />
+            <opt label="optional">
+                {Text("?")}
+            </opt>
             <opt label="type">
                 <pattern action={({ expression }) => expression}>
                     {Text(":")}

diff --git a/test/__snapshots__/generator.test.ts.snap b/test/__snapshots__/generator.test.ts.snap
@@ -90,6 +90,8 @@ exports[`ts-type FunctionType 1`] = `"() => void"`;
 
 exports[`ts-type FunctionType: nested 1`] = `"() => (a: number, b: string) => void"`;
 
+exports[`ts-type FunctionType: optional param 1`] = `"(a: number, b?: string) => number"`;
+
 exports[`ts-type FunctionType: params 1`] = `"(a: number, b: string) => number"`;
 
 exports[`ts-type FunctionType: rest 1`] = `"(...args: any[]) => void"`;

diff --git a/test/assets/ast/FunctionType-OptionalParam.json b/test/assets/ast/FunctionType-OptionalParam.json
@@ -0,0 +1,32 @@
+{
+    "kind": "FunctionType",
+    "params": [
+        {
+            "kind": "FunctionTypeParam",
+            "name": {
+                "kind": "Identifier",
+                "name": "a"
+            },
+            "type": {
+                "kind": "NumberType",
+                "value": "number"
+            }
+        },
+        {
+            "kind": "FunctionTypeParam",
+            "name": {
+                "kind": "Identifier",
+                "name": "b"
+            },
+            "type": {
+                "kind": "StringType",
+                "value": "string"
+            },
+            "optional": true
+        }
+    ],
+    "returnType": {
+        "kind": "NumberType",
+        "value": "number"
+    }
+}
diff --git a/test/assets/ts-type/FunctionType-OptionalParam b/test/assets/ts-type/FunctionType-OptionalParam
@@ -0,0 +1 @@
+(a: number, b?: string) => number
diff --git a/test/generator.test.ts b/test/generator.test.ts
@@ -88,6 +88,11 @@ describe("ts-type", () => {
         expect(toCode(name)).toMatchSnapshot();
     })
 
+    test("FunctionType: optional param", () => {
+        const name = "FunctionType-OptionalParam";
+        expect(toCode(name)).toMatchSnapshot();
+    })
+
     test("FunctionType: params", () => {
         const name = "FunctionType-Params";
         expect(toCode(name)).toMatchSnapshot();

diff --git a/test/parser/__snapshots__/function.test.tsx.snap b/test/parser/__snapshots__/function.test.tsx.snap
@@ -49,6 +49,41 @@ Object {
 }
 `;
 
+exports[`parser: function FunctionType: optional param 1`] = `
+Object {
+  "kind": "FunctionType",
+  "params": Array [
+    Object {
+      "kind": "FunctionTypeParam",
+      "name": Object {
+        "kind": "Identifier",
+        "name": "a",
+      },
+      "type": Object {
+        "kind": "NumberType",
+        "value": "number",
+      },
+    },
+    Object {
+      "kind": "FunctionTypeParam",
+      "name": Object {
+        "kind": "Identifier",
+        "name": "b",
+      },
+      "optional": true,
+      "type": Object {
+        "kind": "StringType",
+        "value": "string",
+      },
+    },
+  ],
+  "returnType": Object {
+    "kind": "NumberType",
+    "value": "number",
+  },
+}
+`;
+
 exports[`parser: function FunctionType: params 1`] = `
 Object {
   "kind": "FunctionType",

diff --git a/test/parser/function.test.tsx b/test/parser/function.test.tsx
@@ -10,6 +10,13 @@ describe("parser: function", () => {
         expect(ast).toMatchSnapshot();
     })
 
+    test("FunctionType: optional param", () => {
+        const parser = ReactPeg.render(<TypeExpression />);
+        const ast = parser.parse(`type (a:number, b?: string) => number`);
+        saveAST(ast, "FunctionType-OptionalParam.json");
+        expect(ast).toMatchSnapshot();
+    })
+
     test("FunctionType: rest", () => {
         const parser = ReactPeg.render(<TypeExpression />);
         const ast = parser.parse(`type (...args: any[]) => void`);