feat: parse mustache expressions inside attribute value strings

Not supporting this was reported in #2 Note that we use a short-cut here to enable mustache statements inside of a string that disallows a `{` to appear inside a "concat statement". Technically this should be allowed, though I would say it's quite rare. Issue #3 was files to keep track of eventually fixing that, though it will likely require moving the scanner into C to pull that off. The problem is that `{` alone is safe, but `{{` together is not, and I'm not sure you can write a regex that TreeSitter supports that can capture that correctly.
ember-tooling · Mar 2, 2021 · 43d0dbd · 43d0dbd
1 parent 1c3d01c
commit 43d0dbd
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Showing 5 changed files with 1,208 additions and 776 deletions.
diff --git a/grammar.js b/grammar.js
@@ -80,11 +80,36 @@ module.exports = grammar({
         optional(
           seq(
             "=",
-            choice($.string_literal, $.number_literal, $.mustache_statement)
+            choice(
+              alias($._mustache_safe_string_literal, $.string_literal),
+              $.concat_statement,
+              $.number_literal,
+              $.mustache_statement
+            )
           )
         )
       ),
 
+    // Special attribute-value strings that can embed a mustache statement
+    concat_statement: ($) =>
+      choice(
+        $._single_quote_concat_statement,
+        $._double_quote_concat_statement
+      ),
+
+    _single_quote_concat_statement: ($) =>
+      prec(1, seq("'", $.mustache_statement, "'")),
+    _double_quote_concat_statement: ($) =>
+      prec(1, seq('"', $.mustache_statement, '"')),
+
+    _mustache_safe_string_literal: ($) =>
+      choice(
+        $._mustache_safe_single_quote_string_literal,
+        $._mustache_safe_double_quote_string_literal
+      ),
+    _mustache_safe_single_quote_string_literal: () => seq("'", /[^'\\{]+/, "'"),
+    _mustache_safe_double_quote_string_literal: () => seq('"', /[^"\\{]+/, '"'),
+
     block_params: ($) => seq("as", "|", repeat($.path_expression), "|"),
 
     // Entering/existing Handlebars expressions

diff --git a/src/grammar.json b/src/grammar.json
@@ -201,9 +201,18 @@
                 {
                   "type": "CHOICE",
                   "members": [
+                    {
+                      "type": "ALIAS",
+                      "content": {
+                        "type": "SYMBOL",
+                        "name": "_mustache_safe_string_literal"
+                      },
+                      "named": true,
+                      "value": "string_literal"
+                    },
                     {
                       "type": "SYMBOL",
-                      "name": "string_literal"
+                      "name": "concat_statement"
                     },
                     {
                       "type": "SYMBOL",
@@ -224,6 +233,108 @@
         }
       ]
     },
+    "concat_statement": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "_single_quote_concat_statement"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_double_quote_concat_statement"
+        }
+      ]
+    },
+    "_single_quote_concat_statement": {
+      "type": "PREC",
+      "value": 1,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "STRING",
+            "value": "'"
+          },
+          {
+            "type": "SYMBOL",
+            "name": "mustache_statement"
+          },
+          {
+            "type": "STRING",
+            "value": "'"
+          }
+        ]
+      }
+    },
+    "_double_quote_concat_statement": {
+      "type": "PREC",
+      "value": 1,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "STRING",
+            "value": "\""
+          },
+          {
+            "type": "SYMBOL",
+            "name": "mustache_statement"
+          },
+          {
+            "type": "STRING",
+            "value": "\""
+          }
+        ]
+      }
+    },
+    "_mustache_safe_string_literal": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "_mustache_safe_single_quote_string_literal"
+        },
+        {
+          "type": "SYMBOL",
+          "name": "_mustache_safe_double_quote_string_literal"
+        }
+      ]
+    },
+    "_mustache_safe_single_quote_string_literal": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "'"
+        },
+        {
+          "type": "PATTERN",
+          "value": "[^'\\\\{]+"
+        },
+        {
+          "type": "STRING",
+          "value": "'"
+        }
+      ]
+    },
+    "_mustache_safe_double_quote_string_literal": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "\""
+        },
+        {
+          "type": "PATTERN",
+          "value": "[^\"\\\\{]+"
+        },
+        {
+          "type": "STRING",
+          "value": "\""
+        }
+      ]
+    },
     "block_params": {
       "type": "SEQ",
       "members": [

diff --git a/src/node-types.json b/src/node-types.json
@@ -11,6 +11,10 @@
           "type": "attribute_name",
           "named": true
         },
+        {
+          "type": "concat_statement",
+          "named": true
+        },
         {
           "type": "mustache_statement",
           "named": true
@@ -46,6 +50,21 @@
     "named": true,
     "fields": {}
   },
+  {
+    "type": "concat_statement",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "mustache_statement",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "element_node",
     "named": true,