From dda63dfd6ee74f3029399f273e144d1cb989c663 Mon Sep 17 00:00:00 2001
From: Simon Holthausen <simon.holthausen@accso.de>
Date: Fri, 19 Feb 2021 14:18:13 +0100
Subject: [PATCH] (fix) named slot element can reference let'ed variable

#817
---
 .../features/DiagnosticsProvider.test.ts      | 106 ++++++++++++++++--
 .../diagnostics-slots-imported.svelte         |   9 ++
 .../testfiles/diagnostics-slots.svelte        |  14 +++
 .../src/htmlxtojsx/nodes/component.ts         |  22 ++--
 .../component-default-slot-empty/expected.jsx |   1 +
 .../component-default-slot-empty/input.svelte |   1 +
 .../samples/component-multi-slot/expected.jsx |   9 +-
 .../samples/component-multi-slot/input.svelte |   7 +-
 .../expected.tsx                              |   4 +-
 9 files changed, 147 insertions(+), 26 deletions(-)
 create mode 100644 packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots-imported.svelte
 create mode 100644 packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots.svelte
 create mode 100644 packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/expected.jsx
 create mode 100644 packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/input.svelte

diff --git a/packages/language-server/test/plugins/typescript/features/DiagnosticsProvider.test.ts b/packages/language-server/test/plugins/typescript/features/DiagnosticsProvider.test.ts
index a1bda880f..4a7a2027c 100644
--- a/packages/language-server/test/plugins/typescript/features/DiagnosticsProvider.test.ts
+++ b/packages/language-server/test/plugins/typescript/features/DiagnosticsProvider.test.ts
@@ -3,19 +3,29 @@ import * as path from 'path';
 import ts from 'typescript';
 import { Document, DocumentManager } from '../../../../src/lib/documents';
 import { LSConfigManager } from '../../../../src/ls-config';
-import { TypeScriptPlugin } from '../../../../src/plugins';
+import { DiagnosticsProviderImpl } from '../../../../src/plugins/typescript/features/DiagnosticsProvider';
+import { LSAndTSDocResolver } from '../../../../src/plugins/typescript/LSAndTSDocResolver';
 import { pathToUrl } from '../../../../src/utils';
 
+const testDir = path.join(__dirname, '..', 'testfiles');
+
 describe('DiagnosticsProvider', () => {
     function setup(filename: string) {
-        const docManager = new DocumentManager(() => document);
-        const testDir = path.join(__dirname, '..');
-        const filePath = path.join(testDir, 'testfiles', filename);
-        const document = new Document(pathToUrl(filePath), ts.sys.readFile(filePath)!);
-        const pluginManager = new LSConfigManager();
-        const plugin = new TypeScriptPlugin(docManager, pluginManager, [pathToUrl(testDir)]);
-        docManager.openDocument(<any>'some doc');
-        return { plugin, document };
+        const docManager = new DocumentManager(
+            (textDocument) => new Document(textDocument.uri, textDocument.text)
+        );
+        const lsAndTsDocResolver = new LSAndTSDocResolver(
+            docManager,
+            [pathToUrl(testDir)],
+            new LSConfigManager()
+        );
+        const plugin = new DiagnosticsProviderImpl(lsAndTsDocResolver);
+        const filePath = path.join(testDir, filename);
+        const document = docManager.openDocument(<any>{
+            uri: pathToUrl(filePath),
+            text: ts.sys.readFile(filePath) || ''
+        });
+        return { plugin, document, docManager };
     }
 
     it('provides diagnostics', async () => {
@@ -311,4 +321,82 @@ describe('DiagnosticsProvider', () => {
             }
         ]);
     });
+
+    it('type-checks slots', async () => {
+        const { plugin, document } = setup('diagnostics-slots.svelte');
+        const diagnostics = await plugin.getDiagnostics(document);
+
+        assert.deepStrictEqual(diagnostics, [
+            {
+                code: 2304,
+                message: "Cannot find name 'defaultSlotProp'.",
+                range: {
+                    end: {
+                        character: 48,
+                        line: 4
+                    },
+                    start: {
+                        character: 33,
+                        line: 4
+                    }
+                },
+                severity: 1,
+                source: 'ts',
+                tags: []
+            },
+            {
+                code: 2367,
+                message:
+                    "This condition will always return 'false' since the types 'number' and 'boolean' have no overlap.",
+                range: {
+                    end: {
+                        character: 28,
+                        line: 6
+                    },
+                    start: {
+                        character: 3,
+                        line: 6
+                    }
+                },
+                severity: 1,
+                source: 'ts',
+                tags: []
+            },
+            {
+                code: 2367,
+                message:
+                    "This condition will always return 'false' since the types 'boolean' and 'number' have no overlap.",
+                range: {
+                    end: {
+                        character: 24,
+                        line: 8
+                    },
+                    start: {
+                        character: 5,
+                        line: 8
+                    }
+                },
+                severity: 1,
+                source: 'ts',
+                tags: []
+            },
+            {
+                code: 2304,
+                message: "Cannot find name 'namedSlotProp'.",
+                range: {
+                    end: {
+                        character: 16,
+                        line: 12
+                    },
+                    start: {
+                        character: 3,
+                        line: 12
+                    }
+                },
+                severity: 1,
+                source: 'ts',
+                tags: []
+            }
+        ]);
+    });
 });
diff --git a/packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots-imported.svelte b/packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots-imported.svelte
new file mode 100644
index 000000000..2e7530a2c
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots-imported.svelte
@@ -0,0 +1,9 @@
+<script lang="ts">
+    export let prop: any;
+    const defaultSlotProp = 1;
+    const namedSlotProp = true;
+</script>
+
+{prop}
+<slot {defaultSlotProp} />
+<slot name="named" {namedSlotProp} />
diff --git a/packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots.svelte b/packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots.svelte
new file mode 100644
index 000000000..dbbf396d0
--- /dev/null
+++ b/packages/language-server/test/plugins/typescript/testfiles/diagnostics-slots.svelte
@@ -0,0 +1,14 @@
+<script lang="ts">
+    import Slots from './diagnostics-slots-imported.svelte';
+</script>
+
+<Slots let:defaultSlotProp prop={defaultSlotProp}>
+  {defaultSlotProp === 1}
+  {defaultSlotProp === false}
+  <p slot="named" let:namedSlotProp class:namedSlotProp>
+    {namedSlotProp === 1}
+    {namedSlotProp === false}
+    {defaultSlotProp}
+  </p>
+  {namedSlotProp}
+</Slots>
diff --git a/packages/svelte2tsx/src/htmlxtojsx/nodes/component.ts b/packages/svelte2tsx/src/htmlxtojsx/nodes/component.ts
index 5dad5709b..235d5df08 100644
--- a/packages/svelte2tsx/src/htmlxtojsx/nodes/component.ts
+++ b/packages/svelte2tsx/src/htmlxtojsx/nodes/component.ts
@@ -42,22 +42,26 @@ function handleSlot(
     slotName: string
 ): void {
     //collect "let" definitions
+    const slotElIsComponent = slotEl === component;
     let hasMoved = false;
-    let afterTag: number;
+    let slotDefInsertionPoint: number;
     for (const attr of slotEl.attributes) {
         if (attr.type != 'Let') {
             continue;
         }
 
-        if (slotEl.children.length == 0) {
+        if (slotElIsComponent && slotEl.children.length == 0) {
             //no children anyway, just wipe out the attribute
             str.remove(attr.start, attr.end);
             continue;
         }
 
-        afterTag = afterTag || htmlx.lastIndexOf('>', slotEl.children[0].start) + 1;
+        slotDefInsertionPoint =
+            slotDefInsertionPoint || slotElIsComponent
+                ? htmlx.lastIndexOf('>', slotEl.children[0].start) + 1
+                : slotEl.start;
 
-        str.move(attr.start, attr.end, afterTag);
+        str.move(attr.start, attr.end, slotDefInsertionPoint);
 
         //remove let:
         if (hasMoved) {
@@ -77,9 +81,11 @@ function handleSlot(
     if (!hasMoved) {
         return;
     }
-    str.appendLeft(afterTag, '{() => { let {');
-    str.appendRight(afterTag, `} = ${getSingleSlotDef(component, slotName)}` + ';<>');
+    str.appendLeft(slotDefInsertionPoint, '{() => { let {');
+    str.appendRight(slotDefInsertionPoint, `} = ${getSingleSlotDef(component, slotName)}` + ';<>');
 
-    const closeTagStart = htmlx.lastIndexOf('<', slotEl.end - 1);
-    str.appendLeft(closeTagStart, '</>}}');
+    const closeSlotDefInsertionPoint = slotElIsComponent
+        ? htmlx.lastIndexOf('<', slotEl.end - 1)
+        : slotEl.end;
+    str.appendLeft(closeSlotDefInsertionPoint, '</>}}');
 }
diff --git a/packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/expected.jsx b/packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/expected.jsx
new file mode 100644
index 000000000..a065bd29d
--- /dev/null
+++ b/packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/expected.jsx
@@ -0,0 +1 @@
+<><Component  ></Component></>
\ No newline at end of file
diff --git a/packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/input.svelte b/packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/input.svelte
new file mode 100644
index 000000000..ae3ec6651
--- /dev/null
+++ b/packages/svelte2tsx/test/htmlx2jsx/samples/component-default-slot-empty/input.svelte
@@ -0,0 +1 @@
+<Component let:var={new_var} let:other_var></Component>
diff --git a/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/expected.jsx b/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/expected.jsx
index 3f9dc7431..6928705eb 100644
--- a/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/expected.jsx
+++ b/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/expected.jsx
@@ -1,8 +1,9 @@
 <><Component >{() => { let {var:new_var} = __sveltets_instanceOf(Component).$$slot_def['default'];<>
-    <h1>Hello</h1>
-    <div  >{() => { let {slotvar:newvar} = __sveltets_instanceOf(Component).$$slot_def['someslot'];<>
-        <h2>Hi Slot</h2>
-    </>}}</div>
+    <h1>Hello {new_var}</h1>
+    {() => { let {slotvar:newvar} = __sveltets_instanceOf(Component).$$slot_def['someslot'];<><div   {...__sveltets_ensureType(Boolean, !!(newvar))}>
+        <h2>Hi Slot {newvar}</h2>
+    </div></>}}
+    {() => { let {newvar2} = __sveltets_instanceOf(Component).$$slot_def['slotwithoutchildren'];<><div   {...__sveltets_ensureType(Boolean, !!(newvar2))}></div></>}}
     <p >
         Test
     </p>
diff --git a/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/input.svelte b/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/input.svelte
index 7b87be787..b7535cdc4 100644
--- a/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/input.svelte
+++ b/packages/svelte2tsx/test/htmlx2jsx/samples/component-multi-slot/input.svelte
@@ -1,8 +1,9 @@
 <Component let:var={new_var}>
-    <h1>Hello</h1>
-    <div slot="someslot" let:slotvar={newvar}>
-        <h2>Hi Slot</h2>
+    <h1>Hello {new_var}</h1>
+    <div slot="someslot" let:slotvar={newvar} class:newvar>
+        <h2>Hi Slot {newvar}</h2>
     </div>
+    <div slot="slotwithoutchildren" let:newvar2 class:newvar2></div>
     <p slot=desc>
         Test
     </p>
diff --git a/packages/svelte2tsx/test/svelte2tsx/samples/component-slot-let-forward-named-slot/expected.tsx b/packages/svelte2tsx/test/svelte2tsx/samples/component-slot-let-forward-named-slot/expected.tsx
index 0b4cf7248..c44873831 100644
--- a/packages/svelte2tsx/test/svelte2tsx/samples/component-slot-let-forward-named-slot/expected.tsx
+++ b/packages/svelte2tsx/test/svelte2tsx/samples/component-slot-let-forward-named-slot/expected.tsx
@@ -1,9 +1,9 @@
 ///<reference types="svelte" />
 <></>;function render() {
 <><Component>
-    <div  >{() => { let {a} = __sveltets_instanceOf(Component).$$slot_def['b'];<>
+    {() => { let {a} = __sveltets_instanceOf(Component).$$slot_def['b'];<><div  >
         <slot a={a}></slot>
-    </>}}</div>
+    </div></>}}
 </Component></>
 return { props: {}, slots: {'default': {a:__sveltets_instanceOf(Component).$$slot_def['b'].a}}, getters: {}, events: {} }}