Prevent runtime errors on FormData set and append (#1534)

ConorLinehan · saschanaz · web-flow · commit c36e4364117a · 2023-03-31T18:34:38.000Z
Co-authored-by: saschanaz &lt;saschanaz@users.noreply.github.com&gt;
diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
@@ -8548,7 +8548,9 @@ interface FontFaceSource {
  */
 interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
-    append(name: string, value: string | Blob, fileName?: string): void;
+    append(name: string, value: string | Blob): void;
+    append(name: string, value: string): void;
+    append(name: string, blobValue: Blob, filename?: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/delete) */
     delete(name: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/get) */
@@ -8558,7 +8560,9 @@ interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/has) */
     has(name: string): boolean;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
-    set(name: string, value: string | Blob, fileName?: string): void;
+    set(name: string, value: string | Blob): void;
+    set(name: string, value: string): void;
+    set(name: string, blobValue: Blob, filename?: string): void;
     forEach(callbackfn: (value: FormDataEntryValue, key: string, parent: FormData) => void, thisArg?: any): void;
 }
 
diff --git a/baselines/serviceworker.generated.d.ts b/baselines/serviceworker.generated.d.ts
@@ -2732,7 +2732,9 @@ interface FontFaceSource {
  */
 interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
-    append(name: string, value: string | Blob, fileName?: string): void;
+    append(name: string, value: string | Blob): void;
+    append(name: string, value: string): void;
+    append(name: string, blobValue: Blob, filename?: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/delete) */
     delete(name: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/get) */
@@ -2742,7 +2744,9 @@ interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/has) */
     has(name: string): boolean;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
-    set(name: string, value: string | Blob, fileName?: string): void;
+    set(name: string, value: string | Blob): void;
+    set(name: string, value: string): void;
+    set(name: string, blobValue: Blob, filename?: string): void;
     forEach(callbackfn: (value: FormDataEntryValue, key: string, parent: FormData) => void, thisArg?: any): void;
 }
 
diff --git a/baselines/sharedworker.generated.d.ts b/baselines/sharedworker.generated.d.ts
@@ -2621,7 +2621,9 @@ interface FontFaceSource {
  */
 interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
-    append(name: string, value: string | Blob, fileName?: string): void;
+    append(name: string, value: string | Blob): void;
+    append(name: string, value: string): void;
+    append(name: string, blobValue: Blob, filename?: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/delete) */
     delete(name: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/get) */
@@ -2631,7 +2633,9 @@ interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/has) */
     has(name: string): boolean;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
-    set(name: string, value: string | Blob, fileName?: string): void;
+    set(name: string, value: string | Blob): void;
+    set(name: string, value: string): void;
+    set(name: string, blobValue: Blob, filename?: string): void;
     forEach(callbackfn: (value: FormDataEntryValue, key: string, parent: FormData) => void, thisArg?: any): void;
 }
 
diff --git a/baselines/webworker.generated.d.ts b/baselines/webworker.generated.d.ts
@@ -2985,7 +2985,9 @@ interface FontFaceSource {
  */
 interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
-    append(name: string, value: string | Blob, fileName?: string): void;
+    append(name: string, value: string | Blob): void;
+    append(name: string, value: string): void;
+    append(name: string, blobValue: Blob, filename?: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/delete) */
     delete(name: string): void;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/get) */
@@ -2995,7 +2997,9 @@ interface FormData {
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/has) */
     has(name: string): boolean;
     /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
-    set(name: string, value: string | Blob, fileName?: string): void;
+    set(name: string, value: string | Blob): void;
+    set(name: string, value: string): void;
+    set(name: string, blobValue: Blob, filename?: string): void;
     forEach(callbackfn: (value: FormDataEntryValue, key: string, parent: FormData) => void, thisArg?: any): void;
 }
 
diff --git a/inputfiles/overridingTypes.jsonc b/inputfiles/overridingTypes.jsonc
@@ -1240,15 +1240,15 @@
                         "append": {
                             "name": "append",
                             "flavor": "Web",
-                            "overrideSignatures": [
-                                "append(name: string, value: string | Blob, fileName?: string): void"
+                            "additionalSignatures": [
+                                "append(name: string, value: string | Blob): void"
                             ]
                         },
                         "set": {
                             "name": "set",
                             "flavor": "Web",
-                            "overrideSignatures": [
-                                "set(name: string, value: string | Blob, fileName?: string): void"
+                            "additionalSignatures": [
+                                "set(name: string, value: string | Blob): void"
                             ]
                         }
                     }
diff --git a/unittests/files/formData.ts b/unittests/files/formData.ts
@@ -0,0 +1,32 @@
+const formData = new FormData();
+
+// Should work
+formData.append("myProp", "value");
+
+// Should work
+formData.append("myProp", new Blob());
+
+// Should work
+formData.append("myProp", new Blob(), "myFile");
+
+// @ts-expect-error will error on runtime
+formData.append("myProp", "value", "myFile");
+
+// Should work
+formData.set("myProp", "value");
+
+// Should work
+formData.set("myProp", new Blob());
+
+// Should work
+formData.set("myProp", new Blob(), "myFile");
+
+// @ts-expect-error will error on runtime
+formData.set("myProp", "value", "myFile");
+
+// Should work for union type
+type stringBlobUnion = string | Blob;
+const unionValue = "value" as stringBlobUnion;
+
+formData.set("myProp", unionValue);
+formData.append("myProp", unionValue);

Original file line number	Diff line number	Diff line change
`@@ -1240,15 +1240,15 @@`
`1240`	`1240`	`"append": {`
`1241`	`1241`	`"name": "append",`
`1242`	`1242`	`"flavor": "Web",`
`1243`		`- "overrideSignatures": [`
`1244`		`- "append(name: string, value: string \| Blob, fileName?: string): void"`
	`1243`	`+ "additionalSignatures": [`
	`1244`	`+ "append(name: string, value: string \| Blob): void"`
`1245`	`1245`	`]`
`1246`	`1246`	`},`
`1247`	`1247`	`"set": {`
`1248`	`1248`	`"name": "set",`
`1249`	`1249`	`"flavor": "Web",`
`1250`		`- "overrideSignatures": [`
`1251`		`- "set(name: string, value: string \| Blob, fileName?: string): void"`
	`1250`	`+ "additionalSignatures": [`
	`1251`	`+ "set(name: string, value: string \| Blob): void"`
`1252`	`1252`	`]`
`1253`	`1253`	`}`
`1254`	`1254`	`}`