From 787cd875b08ef789d2fa203ea1fc4242a1fde587 Mon Sep 17 00:00:00 2001
From: Matthieu Riegler <kyro38@gmail.com>
Date: Tue, 24 Feb 2026 19:28:52 +0100
Subject: [PATCH] refactor(vscode-extension): Add support for exhaustive type
 check in the syntax

`@default never` will be considered a keyword on its own.

(cherry picked from commit db11e74b3d23053c148dd6535099a5a53aaf7fb1)
---
 .../syntaxes/src/template-blocks.ts           | 12 ++++++++-
 .../syntaxes/template-blocks.json             | 24 ++++++++++++++++-
 .../syntaxes/test/data/template-blocks.html   |  5 ++++
 .../test/data/template-blocks.html.snap       | 26 +++++++++++++++++++
 4 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/vscode-ng-language-service/syntaxes/src/template-blocks.ts b/vscode-ng-language-service/syntaxes/src/template-blocks.ts
index e341c44d5fe..a8b5f74cc2f 100644
--- a/vscode-ng-language-service/syntaxes/src/template-blocks.ts
+++ b/vscode-ng-language-service/syntaxes/src/template-blocks.ts
@@ -39,7 +39,7 @@ export const TemplateBlocks: GrammarDefinition = {
         2: {name: 'keyword.control.block.kind.ng'},
       },
       patterns: [{include: '#blockExpression'}],
-      end: /(?=@|{)/,
+      end: /(?=@|{|})/,
       name: 'control.block.case.header.ng',
     },
     caseBlock: {
@@ -48,6 +48,15 @@ export const TemplateBlocks: GrammarDefinition = {
       end: /(?<=\})/,
       name: 'control.block.case.ng',
     },
+    caseExhaustive: {
+      match: /(@)(default\s+never)\s*(;)/,
+      captures: {
+        1: {patterns: [{include: '#transition'}]},
+        2: {name: 'keyword.control.block.kind.ng'},
+        3: {name: 'punctuation.terminator.statement.ng'},
+      },
+      name: 'control.block.case.ng',
+    },
     blockExpression: {
       begin: /\(/,
       beginCaptures: {
@@ -105,6 +114,7 @@ export const TemplateBlocks: GrammarDefinition = {
       },
       contentName: 'control.block.body.ng',
       patterns: [
+        {include: '#caseExhaustive'},
         {include: '#caseBlock'},
         {include: 'text.html.derivative'},
         {include: 'template.ng'},
diff --git a/vscode-ng-language-service/syntaxes/template-blocks.json b/vscode-ng-language-service/syntaxes/template-blocks.json
index cc49bfdf64d..55b5bb8888c 100644
--- a/vscode-ng-language-service/syntaxes/template-blocks.json
+++ b/vscode-ng-language-service/syntaxes/template-blocks.json
@@ -55,7 +55,7 @@
           "include": "#blockExpression"
         }
       ],
-      "end": "(?=@|{)",
+      "end": "(?=@|{|})",
       "name": "control.block.case.header.ng"
     },
     "caseBlock": {
@@ -71,6 +71,25 @@
       "end": "(?<=\\})",
       "name": "control.block.case.ng"
     },
+    "caseExhaustive": {
+      "match": "(@)(default\\s+never)\\s*(;)",
+      "captures": {
+        "1": {
+          "patterns": [
+            {
+              "include": "#transition"
+            }
+          ]
+        },
+        "2": {
+          "name": "keyword.control.block.kind.ng"
+        },
+        "3": {
+          "name": "punctuation.terminator.statement.ng"
+        }
+      },
+      "name": "control.block.case.ng"
+    },
     "blockExpression": {
       "begin": "\\(",
       "beginCaptures": {
@@ -160,6 +179,9 @@
       },
       "contentName": "control.block.body.ng",
       "patterns": [
+        {
+          "include": "#caseExhaustive"
+        },
         {
           "include": "#caseBlock"
         },
diff --git a/vscode-ng-language-service/syntaxes/test/data/template-blocks.html b/vscode-ng-language-service/syntaxes/test/data/template-blocks.html
index 287d58a0e76..e43a1a5d1af 100644
--- a/vscode-ng-language-service/syntaxes/test/data/template-blocks.html
+++ b/vscode-ng-language-service/syntaxes/test/data/template-blocks.html
@@ -18,6 +18,11 @@
     }
 }
 
+@switch(aOrb) {
+    @case(a) {}
+    @default never;
+}
+
 @if (a==b) { hello } @else  { goodbye }
 
 @if (a==b) { 
diff --git a/vscode-ng-language-service/syntaxes/test/data/template-blocks.html.snap b/vscode-ng-language-service/syntaxes/test/data/template-blocks.html.snap
index 320fa528f5f..bc3c7dc51e1 100644
--- a/vscode-ng-language-service/syntaxes/test/data/template-blocks.html.snap
+++ b/vscode-ng-language-service/syntaxes/test/data/template-blocks.html.snap
@@ -104,6 +104,32 @@
 >}
 #^ template.blocks.ng control.block.ng punctuation.definition.block.ts
 >
+>@switch(aOrb) {
+#^ template.blocks.ng control.block.ng keyword.control.block.transition.ng
+# ^^^^^^ template.blocks.ng control.block.ng keyword.control.block.kind.ng
+#       ^ template.blocks.ng control.block.ng meta.brace.round.ts
+#        ^^^^ template.blocks.ng control.block.ng control.block.expression.ng variable.other.readwrite.ts
+#            ^ template.blocks.ng control.block.ng meta.brace.round.ts
+#             ^ template.blocks.ng control.block.ng
+#              ^ template.blocks.ng control.block.ng punctuation.definition.block.ts
+>    @case(a) {}
+#^^^^ template.blocks.ng control.block.ng control.block.body.ng
+#    ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng control.block.case.header.ng keyword.control.block.transition.ng
+#     ^^^^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng control.block.case.header.ng keyword.control.block.kind.ng
+#         ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng control.block.case.header.ng meta.brace.round.ts
+#          ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng control.block.case.header.ng control.block.expression.ng variable.other.readwrite.ts
+#           ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng control.block.case.header.ng meta.brace.round.ts
+#            ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng control.block.case.header.ng
+#             ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng punctuation.definition.block.ts
+#              ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng punctuation.definition.block.ts
+>    @default never;
+#^^^^ template.blocks.ng control.block.ng control.block.body.ng
+#    ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng keyword.control.block.transition.ng
+#     ^^^^^^^^^^^^^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng keyword.control.block.kind.ng
+#                  ^ template.blocks.ng control.block.ng control.block.body.ng control.block.case.ng punctuation.terminator.statement.ng
+>}
+#^ template.blocks.ng control.block.ng punctuation.definition.block.ts
+>
 >@if (a==b) { hello } @else  { goodbye }
 #^ template.blocks.ng control.block.ng keyword.control.block.transition.ng
 # ^^ template.blocks.ng control.block.ng keyword.control.block.kind.ng