From e118ab02cbc006b1fe73bab8ab8fe221d36136ca Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@vercel.com>
Date: Thu, 18 Apr 2024 15:59:28 +0200
Subject: [PATCH] mark exports as "can only bind to them"

---
 .../fixtures/bind-this/expected_svelte_5.json |  2 +-
 .../fixtures/bindings/Legacy.svelte           |  6 ++++
 .../fixtures/bindings/Runes.svelte            |  7 ++++
 .../fixtures/bindings/expected_svelte_5.json  | 36 +++++++++++++++++++
 .../fixtures/bindings/expectedv2.json         |  1 +
 .../fixtures/bindings/input.svelte            | 25 +++++++++++++
 .../src/svelte2tsx/nodes/ExportedNames.ts     | 22 +++++++++---
 .../expected/TestRunes.svelte.d.ts            |  4 +--
 .../expectedv2.ts                             |  2 +-
 .../expectedv2.ts                             |  2 +-
 .../expectedv2.ts                             |  2 +-
 .../expectedv2.ts                             |  2 +-
 12 files changed, 99 insertions(+), 12 deletions(-)
 create mode 100644 packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Legacy.svelte
 create mode 100644 packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Runes.svelte
 create mode 100644 packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expected_svelte_5.json
 create mode 100644 packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expectedv2.json
 create mode 100644 packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/input.svelte

diff --git a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bind-this/expected_svelte_5.json b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bind-this/expected_svelte_5.json
index 02e74721f..09171f654 100644
--- a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bind-this/expected_svelte_5.json
+++ b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bind-this/expected_svelte_5.json
@@ -36,7 +36,7 @@
         },
         "severity": 1,
         "source": "ts",
-        "message": "Type 'Component' is not assignable to type 'OtherComponent'.\n  Types of property '$$prop_def' are incompatible.\n    Type 'StripBindable<PropsWithChildren<{ prop: boolean; }, any>>' is not assignable to type 'StripBindable<PropsWithChildren<{ prop: string; }, any>>'.\n      Type 'StripBindable<WithBindings<{ prop: boolean; }>>' is not assignable to type 'StripBindable<PropsWithChildren<{ prop: string; }, any>>'.",
+        "message": "Type 'Component' is not assignable to type 'OtherComponent'.\n  The types of '$$prop_def.prop' are incompatible between these types.\n    Type 'boolean' is not assignable to type 'string'.",
         "code": 2322,
         "tags": []
     },
diff --git a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Legacy.svelte b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Legacy.svelte
new file mode 100644
index 000000000..1bd159644
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Legacy.svelte
@@ -0,0 +1,6 @@
+<script lang="ts">
+    export let value = 'implicitly bindable';
+    export function bind_and_prop() {
+        return true;
+    }
+</script>
diff --git a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Runes.svelte b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Runes.svelte
new file mode 100644
index 000000000..34b9e88d7
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/Runes.svelte
@@ -0,0 +1,7 @@
+<script lang="ts">
+    let { readonly, can_bind = $bindable() }: { readonly?: string; can_bind?: string } = $props();
+
+    export function only_bind() {
+        return true;
+    }
+</script>
diff --git a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expected_svelte_5.json b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expected_svelte_5.json
new file mode 100644
index 000000000..8c6a50806
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expected_svelte_5.json
@@ -0,0 +1,36 @@
+[
+    {
+        "code": 2322,
+        "message": "Type 'Binding<string>' is not assignable to type 'string'.",
+        "range": {
+            "end": {
+                "character": 20,
+                "line": 23
+            },
+            "start": {
+                "character": 12,
+                "line": 23
+            }
+        },
+        "severity": 1,
+        "source": "ts",
+        "tags": []
+    },
+    {
+        "code": 2322,
+        "message": "Type '() => boolean' is not assignable to type 'Binding<() => boolean>'.",
+        "range": {
+            "end": {
+                "character": 17,
+                "line": 24
+            },
+            "start": {
+                "character": 8,
+                "line": 24
+            }
+        },
+        "severity": 1,
+        "source": "ts",
+        "tags": []
+    }
+]
diff --git a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expectedv2.json b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expectedv2.json
new file mode 100644
index 000000000..fe51488c7
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/expectedv2.json
@@ -0,0 +1 @@
+[]
diff --git a/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/input.svelte b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/input.svelte
new file mode 100644
index 000000000..3978c6f17
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/features/diagnostics/fixtures/bindings/input.svelte
@@ -0,0 +1,25 @@
+<script lang="ts">
+    import Legacy from './Legacy.svelte';
+    import Runes from './Runes.svelte';
+
+    let bind_and_prop: () => boolean;
+    let value = '';
+
+    let only_bind: () => boolean;
+    let can_bind = '';
+    let readonly = ''
+</script>
+
+<!-- ok -->
+<Legacy bind:bind_and_prop />
+<Legacy bind:value />
+<Legacy {value} />
+<Legacy {bind_and_prop} />
+<Runes bind:can_bind />
+<Runes {can_bind} />
+<Runes {readonly} />
+<Runes bind:only_bind />
+
+<!-- error in Svelte 5 -->
+<Runes bind:readonly />
+<Runes {only_bind} />
diff --git a/packages/svelte2tsx/src/svelte2tsx/nodes/ExportedNames.ts b/packages/svelte2tsx/src/svelte2tsx/nodes/ExportedNames.ts
index a99808643..a66330012 100644
--- a/packages/svelte2tsx/src/svelte2tsx/nodes/ExportedNames.ts
+++ b/packages/svelte2tsx/src/svelte2tsx/nodes/ExportedNames.ts
@@ -610,7 +610,12 @@ export class ExportedNames {
                     ? `__sveltets_2_Bindings<${this.$props.type}, ${this.$props.bindings.map((b) => `"${b}"`).join('|')}>`
                     : this.$props.type) +
                 (others.length
-                    ? ' & { ' + this.createReturnElementsType(others).join(',') + ' }'
+                    ? ' & { ' +
+                      this.createReturnElementsType(others, undefined, [
+                          'import("svelte").Binding<',
+                          '>'
+                      ]).join(',') +
+                      ' }'
                     : '')
             );
         }
@@ -630,7 +635,7 @@ export class ExportedNames {
                         return (
                             this.$props.comment.slice(0, idx) +
                             (others.length > 0
-                                ? `{${this.createReturnElementsType(others, false)}} & `
+                                ? `{${this.createReturnElementsType(others, false, ['import("svelte").Binding<', '>'])}} & `
                                 : '') +
                             (has_bindings ? '__sveltets_2_Bindings<' : '') +
                             this.$props.comment.slice(idx, end) +
@@ -700,16 +705,23 @@ export class ExportedNames {
         });
     }
 
-    private createReturnElementsType(names: Array<[string, ExportedName]>, addDoc = true) {
+    private createReturnElementsType(
+        names: Array<[string, ExportedName]>,
+        addDoc = true,
+        wrapWith?: [string, string]
+    ) {
+        const wrap = wrapWith
+            ? (str: string) => `${wrapWith[0]}${str}${wrapWith[1]}`
+            : (str: string) => str;
         return names.map(([key, value]) => {
             const identifier = `${value.doc && addDoc ? `\n${value.doc}` : ''}${
                 value.identifierText || key
             }${value.required ? '' : '?'}`;
             if (!value.type) {
-                return `${identifier}: typeof ${key}`;
+                return `${identifier}: ${wrap(`typeof ${key}`)}`;
             }
 
-            return `${identifier}: ${value.type}`;
+            return `${identifier}: ${wrap(value.type)}`;
         });
     }
 
diff --git a/packages/svelte2tsx/test/emitDts/samples/typescript-runes.v5/expected/TestRunes.svelte.d.ts b/packages/svelte2tsx/test/emitDts/samples/typescript-runes.v5/expected/TestRunes.svelte.d.ts
index 98230cac5..619e8bd8a 100644
--- a/packages/svelte2tsx/test/emitDts/samples/typescript-runes.v5/expected/TestRunes.svelte.d.ts
+++ b/packages/svelte2tsx/test/emitDts/samples/typescript-runes.v5/expected/TestRunes.svelte.d.ts
@@ -3,7 +3,7 @@ declare const __propDef: {
     props: {
         foo: string;
         bar?: import("svelte").Bindable<number>;
-        baz?: () => void;
+        baz?: import("svelte").Binding<() => void>;
     };
     events: {
         [evt: string]: CustomEvent<any>;
@@ -17,7 +17,7 @@ export default class TestRunes extends SvelteComponent<TestRunesProps, TestRunes
     constructor(options?: import("svelte").ComponentConstructorOptions<{
         foo: string;
         bar?: import("svelte").Bindable<number>;
-        baz?: () => void;
+        baz?: import("svelte").Binding<() => void>;
     }>);
     get baz(): () => void;
 }
diff --git a/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune-no-changes/expectedv2.ts b/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune-no-changes/expectedv2.ts
index a6fd870bf..9f526ad45 100644
--- a/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune-no-changes/expectedv2.ts
+++ b/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune-no-changes/expectedv2.ts
@@ -7,7 +7,7 @@
      const snapshot = {};
 ;
 async () => {};
-return { props: /** @type {{snapshot?: typeof snapshot} & $$ComponentProps} */({}), slots: {}, events: {} }}
+return { props: /** @type {{snapshot?: import("svelte").Binding<typeof snapshot>} & $$ComponentProps} */({}), slots: {}, events: {} }}
 
 export default class Page__SvelteComponent_ extends __sveltets_2_createSvelte2TsxComponent(__sveltets_2_partial(['snapshot'], __sveltets_2_with_any_event(render()))) {
     constructor(options = __sveltets_2_runes_constructor(__sveltets_2_partial(['snapshot'], __sveltets_2_with_any_event(render())))) { super(options); }
diff --git a/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune/expectedv2.ts b/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune/expectedv2.ts
index b0b79ef83..ee256ab79 100644
--- a/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune/expectedv2.ts
+++ b/packages/svelte2tsx/test/svelte2tsx/samples/sveltekit-autotypes-$props-rune/expectedv2.ts
@@ -5,7 +5,7 @@
      const snapshot/*Ωignore_startΩ*/: import('./$types.js').Snapshot/*Ωignore_endΩ*/ = {};
 ;
 async () => {};
-return { props: /** @type {{snapshot?: typeof snapshot} & $$ComponentProps} */({}), slots: {}, events: {} }}
+return { props: /** @type {{snapshot?: import("svelte").Binding<typeof snapshot>} & $$ComponentProps} */({}), slots: {}, events: {} }}
 
 export default class Page__SvelteComponent_ extends __sveltets_2_createSvelte2TsxComponent(__sveltets_2_partial(['snapshot'], __sveltets_2_with_any_event(render()))) {
     constructor(options = __sveltets_2_runes_constructor(__sveltets_2_partial(['snapshot'], __sveltets_2_with_any_event(render())))) { super(options); }
diff --git a/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune-unchanged/expectedv2.ts b/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune-unchanged/expectedv2.ts
index 42c9a6030..0b709e340 100644
--- a/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune-unchanged/expectedv2.ts
+++ b/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune-unchanged/expectedv2.ts
@@ -5,7 +5,7 @@
     let { form, data }:$$ComponentProps = $props();
 ;
 async () => {};
-return { props: {} as any as $$ComponentProps & { snapshot?: any }, slots: {}, events: {} }}
+return { props: {} as any as $$ComponentProps & { snapshot?: import("svelte").Binding<any> }, slots: {}, events: {} }}
 
 export default class Page__SvelteComponent_ extends __sveltets_2_createSvelte2TsxComponent(__sveltets_2_with_any_event(render())) {
     constructor(options = __sveltets_2_runes_constructor(__sveltets_2_with_any_event(render()))) { super(options); }
diff --git a/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune/expectedv2.ts b/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune/expectedv2.ts
index 3be5dd593..72746c967 100644
--- a/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune/expectedv2.ts
+++ b/packages/svelte2tsx/test/svelte2tsx/samples/ts-sveltekit-autotypes-$props-rune/expectedv2.ts
@@ -5,7 +5,7 @@
     let { form, data }: $$ComponentProps = $props();
 ;
 async () => {};
-return { props: {} as any as $$ComponentProps & { snapshot?: typeof snapshot }, slots: {}, events: {} }}
+return { props: {} as any as $$ComponentProps & { snapshot?: import("svelte").Binding<typeof snapshot> }, slots: {}, events: {} }}
 
 export default class Page__SvelteComponent_ extends __sveltets_2_createSvelte2TsxComponent(__sveltets_2_with_any_event(render())) {
     constructor(options = __sveltets_2_runes_constructor(__sveltets_2_with_any_event(render()))) { super(options); }