From 9fcf918e61cdb78f7a2e55af64362ad469a92aee Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Thu, 2 Oct 2025 13:00:31 +0200
Subject: [PATCH 01/18] add dependency on Ohm wasm packages

---
 packages/liquid-html-parser/package.json   |  1 +
 packages/liquid-html-parser/src/grammar.ts |  2 +-
 yarn.lock                                  | 12 ++++++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index 6e523db09..1fd84c2cc 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -32,6 +32,7 @@
     "type-check": "tsc --noEmit"
   },
   "dependencies": {
+    "@ohm-js/wasm": "^0.6.2",
     "line-column": "^1.0.2",
     "ohm-js": "^17.0.0"
   },
diff --git a/packages/liquid-html-parser/src/grammar.ts b/packages/liquid-html-parser/src/grammar.ts
index 2d91f00fd..e43266c6d 100644
--- a/packages/liquid-html-parser/src/grammar.ts
+++ b/packages/liquid-html-parser/src/grammar.ts
@@ -1,4 +1,4 @@
-import { grammars, Grammar } from 'ohm-js';
+import { grammars, Grammar } from '@ohm-js/wasm/compat';
 
 export const liquidHtmlGrammars = grammars(require('../grammar/liquid-html.ohm.js'));
 
diff --git a/yarn.lock b/yarn.lock
index 826ef7afc..9f8939171 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -909,6 +909,13 @@
     "@nodelib/fs.scandir" "2.1.5"
     fastq "^1.6.0"
 
+"@ohm-js/wasm@^0.6.2":
+  version "0.6.2"
+  resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.2.tgz#a1c33a859cb62e2f87541f42a8a729b7a0b9aaa3"
+  integrity sha512-kWmF4oSa7r0t91xd36pzXPyGi0FQDmBHoTeY/VA2AMStvs+2iyQ1qnN01RjhbIfiza2v0YLXjDfmainCEHuPeA==
+  dependencies:
+    "@wasmgroundup/emit" "^1.0.2"
+
 "@playwright/browser-chromium@^1.47.2":
   version "1.48.0"
   resolved "https://registry.npmjs.org/@playwright/browser-chromium/-/browser-chromium-1.48.0.tgz#780ca1ebe1aa34dbffa117267c5a84077ed784d0"
@@ -1758,6 +1765,11 @@
   resolved "https://registry.npmjs.org/@vscode/web-custom-data/-/web-custom-data-0.4.6.tgz"
   integrity sha512-4zen0CzChZ0cvVqttxe9B+G56M3A0pMoaG6Y9784EN2zvr5n61m6JebfYhJ5rzINbTqePEqmwG+7tsdr5g9BJA==
 
+"@wasmgroundup/emit@^1.0.2":
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/@wasmgroundup/emit/-/emit-1.0.2.tgz#8d428e98468562b745aa584ac259334765c7826b"
+  integrity sha512-9FupNg9RUOQIBe2zNp0DY78Rb03xeElaL9NQB4haz+JDOF+0Bq4tNSuB/vwG4DFTKSffBKFCa85YdVZaf5vQPw==
+
 "@webassemblyjs/ast@1.14.1", "@webassemblyjs/ast@^1.12.1":
   version "1.14.1"
   resolved "https://registry.yarnpkg.com/@webassemblyjs/ast/-/ast-1.14.1.tgz#a9f6a07f2b03c95c8d38c4536a1fdfb521ff55b6"

From 4aa462803d9f3b2b10304ebd1a6b0acb44708c1d Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Tue, 7 Oct 2025 10:33:56 +0200
Subject: [PATCH 02/18] package.json: Change moduleResolution to node16

---
 tsconfig.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tsconfig.json b/tsconfig.json
index 7cc798d6d..2be1d643e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -26,7 +26,7 @@
     /* Modules */
     "module": "commonjs", /* Specify what module code is generated. */
     "rootDir": ".", /* Specify the root folder within your source files. */
-    "moduleResolution": "node", /* Specify how TypeScript looks up a file from a given module specifier. */
+    "moduleResolution": "node16", /* Specify how TypeScript looks up a file from a given module specifier. */
     // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
     "paths": {
       "@shopify/theme-check-common": [

From 0a041435fedad20cd689477ebf8c7f4d2c60df8e Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Mon, 22 Sep 2025 10:24:49 +0200
Subject: [PATCH 03/18] pld: refactor to use AstBuilder

---
 packages/liquid-html-parser/package.json      |  1 +
 .../liquid-html-parser/src/stage-1-cst.ts     | 73 +++++++------------
 yarn.lock                                     |  5 ++
 3 files changed, 32 insertions(+), 47 deletions(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index 1fd84c2cc..da913545c 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -37,6 +37,7 @@
     "ohm-js": "^17.0.0"
   },
   "devDependencies": {
+    "@ohm-js/miniohm-js": "^0.3.6",
     "@types/line-column": "^1.0.0"
   }
 }
diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index f28bd0891..012fb871b 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -32,7 +32,8 @@
 
 import { Parser } from 'prettier';
 import { Grammar, Node } from 'ohm-js';
-import { toAST } from 'ohm-js/extras';
+import { AstBuilder } from '@ohm-js/wasm';
+
 import {
   LiquidDocGrammar,
   LiquidGrammars,
@@ -602,10 +603,7 @@ function toCST<T>(
     empty: () => null,
     nonemptyOrderedListOf: 0,
     nonemptyOrderedListOfBoth(nonemptyListOfA: Node, _sep: Node, nonemptyListOfB: Node) {
-      const self = this as any;
-      return nonemptyListOfA
-        .toAST(self.args.mapping)
-        .concat(nonemptyListOfB.toAST(self.args.mapping));
+      return this.toAst(nonemptyListOfA).concat(this.toAst(nonemptyListOfB));
     },
   };
 
@@ -734,7 +732,7 @@ function toCST<T>(
         const markupNode = nodes[6];
         const nameNode = nodes[3];
         if (NamedTags.hasOwnProperty(nameNode.sourceString)) {
-          return markupNode.toAST((this as any).args.mapping);
+          return this.toAst(markupNode);
         }
         return markupNode.sourceString.trim();
       },
@@ -830,7 +828,7 @@ function toCST<T>(
         const markupNode = nodes[6];
         const nameNode = nodes[3];
         if (NamedTags.hasOwnProperty(nameNode.sourceString)) {
-          return markupNode.toAST((this as any).args.mapping);
+          return this.toAst(markupNode);
         }
         return markupNode.sourceString.trim();
       },
@@ -906,12 +904,10 @@ function toCST<T>(
       variableLookup,
       _7,
     ) {
-      const self = this as any;
-
       // variableLookup.sourceString can be '' when there are no incomplete params
-      return namedArguments
-        .toAST(self.args.mapping)
-        .concat(variableLookup.sourceString === '' ? [] : variableLookup.toAST(self.args.mapping));
+      return this.toAst(namedArguments).concat(
+        variableLookup.sourceString === '' ? [] : this.toAst(variableLookup),
+      );
     },
     snippetExpression: 0,
     renderVariableExpression: {
@@ -969,30 +965,24 @@ function toCST<T>(
         if (nodes[7].sourceString === '') {
           return [];
         } else {
-          return nodes[7].toAST((this as any).args.mapping);
+          return this.toAst(nodes[7]);
         }
       },
     },
     filterArguments: 0,
     arguments: 0,
     complexArguments: function (completeParams, _space1, _comma, _space2, incompleteParam) {
-      const self = this as any;
-
-      return completeParams
-        .toAST(self.args.mapping)
-        .concat(
-          incompleteParam.sourceString === '' ? [] : incompleteParam.toAST(self.args.mapping),
-        );
+      return this.toAst(completeParams).concat(
+        incompleteParam.sourceString === '' ? [] : this.toAst(incompleteParam),
+      );
     },
     simpleArgument: 0,
     tagArguments: 0,
     contentForTagArgument: 0,
     completionModeContentForTagArgument: function (namedArguments, _separator, variableLookup) {
-      const self = this as any;
-
-      return namedArguments
-        .toAST(self.args.mapping)
-        .concat(variableLookup.sourceString === '' ? [] : variableLookup.toAST(self.args.mapping));
+      return this.toAst(namedArguments).concat(
+        variableLookup.sourceString === '' ? [] : this.toAst(variableLookup),
+      );
     },
     positionalArgument: 0,
     namedArgument: {
@@ -1014,12 +1004,8 @@ function toCST<T>(
     },
 
     liquidBooleanExpression(initialCondition: Node, subsequentConditions: Node) {
-      const initialConditionAst = initialCondition.toAST(
-        (this as any).args.mapping,
-      ) as ConcreteLiquidCondition;
-      const subsequentConditionAsts = subsequentConditions.toAST(
-        (this as any).args.mapping,
-      ) as ConcreteLiquidCondition[];
+      const initialConditionAst = this.toAst(initialCondition) as ConcreteLiquidCondition;
+      const subsequentConditionAsts = this.toAst(subsequentConditions) as ConcreteLiquidCondition[];
 
       // liquidBooleanExpression can capture too much. If there are no comparisons (e.g. `==`, `>`, etc.)
       // and we only have a single condition (i.e. no `and` or `or` operators), we can return the expression directly.
@@ -1145,7 +1131,7 @@ function toCST<T>(
         const markupNode = nodes[2];
         const nameNode = nodes[0];
         if (NamedTags.hasOwnProperty(nameNode.sourceString)) {
-          return markupNode.toAST((this as any).args.mapping);
+          return this.toAst(markupNode);
         }
         return markupNode.sourceString.trim();
       },
@@ -1173,7 +1159,7 @@ function toCST<T>(
         const markupNode = nodes[2];
         const nameNode = nodes[0];
         if (NamedTags.hasOwnProperty(nameNode.sourceString)) {
-          return markupNode.toAST((this as any).args.mapping);
+          return this.toAst(markupNode);
         }
         return markupNode.sourceString.trim();
       },
@@ -1260,11 +1246,10 @@ function toCST<T>(
 
   const LiquidHTMLMappings: Mapping = {
     Node(frontmatter: Node, nodes: Node) {
-      const self = this as any;
       const frontmatterNode =
-        frontmatter.sourceString.length === 0 ? [] : [frontmatter.toAST(self.args.mapping)];
+        frontmatter.sourceString.length === 0 ? [] : [this.toAst(frontmatter)];
 
-      return frontmatterNode.concat(nodes.toAST(self.args.mapping));
+      return frontmatterNode.concat(this.toAst(nodes));
     },
 
     yamlFrontmatter: {
@@ -1295,8 +1280,7 @@ function toCST<T>(
       type: ConcreteNodeTypes.HtmlRawTag,
       name: (tokens: Node[]) => tokens[0].children[1].sourceString,
       attrList(tokens: Node[]) {
-        const mappings = (this as any).args.mapping;
-        return tokens[0].children[2].toAST(mappings);
+        return this.toAst(tokens[0].children[2]);
       },
       body: (tokens: Node[]) => source.slice(tokens[0].source.endIdx, tokens[2].source.startIdx),
       children: (tokens: Node[]) => {
@@ -1359,8 +1343,7 @@ function toCST<T>(
     trailingTagNamePart: 0,
     trailingTagNameTextNode: textNode,
     tagName(leadingPart: Node, trailingParts: Node) {
-      const mappings = (this as any).args.mapping;
-      return [leadingPart.toAST(mappings)].concat(trailingParts.toAST(mappings));
+      return [this.toAst(leadingPart)].concat(this.toAst(trailingParts));
     },
 
     AttrUnquoted: {
@@ -1422,8 +1405,7 @@ function toCST<T>(
     }),
     {},
   );
-
-  return toAST(res, selectedMappings) as T;
+  return new AstBuilder(selectedMappings).toAst(res) as T;
 }
 
 /**
@@ -1457,12 +1439,9 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
 
   const LiquidDocMappings: Mapping = {
     Node(implicitDescription: Node, body: Node) {
-      const self = this as any;
       const implicitDescriptionNode =
-        implicitDescription.sourceString.length === 0
-          ? []
-          : [implicitDescription.toAST(self.args.mapping)];
-      return implicitDescriptionNode.concat(body.toAST(self.args.mapping));
+        implicitDescription.sourceString.length === 0 ? [] : [this.toAst(implicitDescription)];
+      return implicitDescriptionNode.concat(this.toAst(body));
     },
     ImplicitDescription: {
       type: ConcreteNodeTypes.LiquidDocDescriptionNode,
diff --git a/yarn.lock b/yarn.lock
index 9f8939171..aa7bb93dc 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -909,6 +909,11 @@
     "@nodelib/fs.scandir" "2.1.5"
     fastq "^1.6.0"
 
+"@ohm-js/miniohm-js@^0.3.6":
+  version "0.3.6"
+  resolved "https://registry.yarnpkg.com/@ohm-js/miniohm-js/-/miniohm-js-0.3.6.tgz#d6bafe987db7e1963e703ab9040ae3af474883f4"
+  integrity sha512-GWsbhyRdKxxhM2MG8z40/dgQe0w3rZCOdzHXJVfTpUxN1k0gFy+dNyJWtVr9XCZfXQ+p0EV/0HkN48pmQo0xVg==
+
 "@ohm-js/wasm@^0.6.2":
   version "0.6.2"
   resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.2.tgz#a1c33a859cb62e2f87541f42a8a729b7a0b9aaa3"

From 22537b1e44e468b8c9e08806d49a470b55544a9f Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Mon, 22 Sep 2025 19:45:47 +0200
Subject: [PATCH 04/18] pld: fix some issues due to different Cst format

---
 packages/liquid-html-parser/package.json       |  1 +
 packages/liquid-html-parser/src/stage-1-cst.ts | 12 ++++++------
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index da913545c..044a4d1d3 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -38,6 +38,7 @@
   },
   "devDependencies": {
     "@ohm-js/miniohm-js": "^0.3.6",
+    "@ohm-js/wasm": "^0.3.3",
     "@types/line-column": "^1.0.0"
   }
 }
diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 012fb871b..e132132ca 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -945,7 +945,7 @@ function toCST<T>(
       expression: 0,
       filters: 1,
       rawSource: (tokens: Node[]) =>
-        source.slice(locStart(tokens), tokens[tokens.length - 2].source.endIdx).trimEnd(),
+        source.slice(locStart(tokens), tokens[tokens.length - 1].source.endIdx).trimEnd(),
       locStart,
       // The last node of this rule is a positive lookahead, we don't
       // want its endIdx, we want the endIdx of the previous one.
@@ -960,13 +960,13 @@ function toCST<T>(
       locEnd,
       source,
       args(nodes: Node[]) {
-        // Traditinally, this would get transformed into null or array. But
-        // it's better if we have an empty array instead of null here.
-        if (nodes[7].sourceString === '') {
+        if (nodes[4].sourceString === '') {
+          // Traditionally, this would get transformed into null or array. But
+          // it's better if we have an empty array instead of null here.
           return [];
-        } else {
-          return this.toAst(nodes[7]);
         }
+        const argumentsNode = nodes[4].children[3];
+        return this.toAst(argumentsNode);
       },
     },
     filterArguments: 0,

From f7de78f959a8a31243208c63c278fc90160d5ba9 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Tue, 23 Sep 2025 19:38:33 +0200
Subject: [PATCH 05/18] pld: fix some issues due to diff't arity of iter nodes

---
 packages/liquid-html-parser/package.json       | 2 +-
 packages/liquid-html-parser/src/stage-1-cst.ts | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index 044a4d1d3..e40ba5220 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -37,7 +37,7 @@
     "ohm-js": "^17.0.0"
   },
   "devDependencies": {
-    "@ohm-js/miniohm-js": "^0.3.6",
+    "@ohm-js/miniohm-js": "^0.3.7",
     "@ohm-js/wasm": "^0.3.3",
     "@types/line-column": "^1.0.0"
   }
diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index e132132ca..5e42c5b02 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -867,7 +867,7 @@ function toCST<T>(
     liquidTagCycleMarkup: {
       type: ConcreteNodeTypes.CycleMarkup,
       groupName: 0,
-      args: 3,
+      args: 2,
       locStart,
       locEnd,
       source,
@@ -997,7 +997,7 @@ function toCST<T>(
     contentForNamedArgument: {
       type: ConcreteNodeTypes.NamedArgument,
       name: (node) => node[0].sourceString + node[1].sourceString,
-      value: 6,
+      value: 5,
       locStart,
       locEnd,
       source,
@@ -1228,8 +1228,8 @@ function toCST<T>(
       source,
       blockStartLocStart: (tokens: Node[]) => offset + tokens[0].source.startIdx,
       blockStartLocEnd: (tokens: Node[]) => offset + tokens[0].source.endIdx,
-      blockEndLocStart: (tokens: Node[]) => offset + tokens[4].source.startIdx,
-      blockEndLocEnd: (tokens: Node[]) => offset + tokens[4].source.endIdx,
+      blockEndLocStart: (tokens: Node[]) => offset + tokens[3].source.startIdx,
+      blockEndLocEnd: (tokens: Node[]) => offset + tokens[3].source.endIdx,
     },
 
     liquidInlineComment: {

From 970c3279b08e61d7fb7f7ea487d7aa86705fcdcd Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 24 Sep 2025 12:02:16 +0200
Subject: [PATCH 06/18] pld: fix more issues

---
 packages/liquid-html-parser/package.json       | 2 --
 packages/liquid-html-parser/src/stage-1-cst.ts | 4 ++--
 yarn.lock                                      | 5 -----
 3 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index e40ba5220..1fd84c2cc 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -37,8 +37,6 @@
     "ohm-js": "^17.0.0"
   },
   "devDependencies": {
-    "@ohm-js/miniohm-js": "^0.3.7",
-    "@ohm-js/wasm": "^0.3.3",
     "@types/line-column": "^1.0.0"
   }
 }
diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 5e42c5b02..46f104acf 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -583,7 +583,7 @@ function toCST<T>(
   const textNode = {
     type: ConcreteNodeTypes.TextNode,
     value: function () {
-      return (this as any).sourceString;
+      return this.currNode.sourceString;
     },
     locStart,
     locEnd,
@@ -1430,7 +1430,7 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
   const textNode = () => ({
     type: ConcreteNodeTypes.TextNode,
     value: function () {
-      return (this as any).sourceString;
+      return this.currNode.sourceString;
     },
     locStart,
     locEnd,
diff --git a/yarn.lock b/yarn.lock
index aa7bb93dc..9f8939171 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -909,11 +909,6 @@
     "@nodelib/fs.scandir" "2.1.5"
     fastq "^1.6.0"
 
-"@ohm-js/miniohm-js@^0.3.6":
-  version "0.3.6"
-  resolved "https://registry.yarnpkg.com/@ohm-js/miniohm-js/-/miniohm-js-0.3.6.tgz#d6bafe987db7e1963e703ab9040ae3af474883f4"
-  integrity sha512-GWsbhyRdKxxhM2MG8z40/dgQe0w3rZCOdzHXJVfTpUxN1k0gFy+dNyJWtVr9XCZfXQ+p0EV/0HkN48pmQo0xVg==
-
 "@ohm-js/wasm@^0.6.2":
   version "0.6.2"
   resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.2.tgz#a1c33a859cb62e2f87541f42a8a729b7a0b9aaa3"

From f24ea44405be3890452c2c8b6e2af1d348a391a5 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Thu, 25 Sep 2025 16:59:40 +0200
Subject: [PATCH 07/18] pld: get rid of locEndSecondToLast (lookahead no longer
 binds)

---
 packages/liquid-html-parser/src/stage-1-cst.ts | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 46f104acf..2aa739871 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -578,7 +578,6 @@ function toCST<T>(
   // for the offset of the {% liquid %} markup
   const locStart = (tokens: Node[]) => offset + tokens[0].source.startIdx;
   const locEnd = (tokens: Node[]) => offset + tokens[tokens.length - 1].source.endIdx;
-  const locEndSecondToLast = (tokens: Node[]) => offset + tokens[tokens.length - 2].source.endIdx;
 
   const textNode = {
     type: ConcreteNodeTypes.TextNode,
@@ -947,9 +946,7 @@ function toCST<T>(
       rawSource: (tokens: Node[]) =>
         source.slice(locStart(tokens), tokens[tokens.length - 1].source.endIdx).trimEnd(),
       locStart,
-      // The last node of this rule is a positive lookahead, we don't
-      // want its endIdx, we want the endIdx of the previous one.
-      locEnd: locEndSecondToLast,
+      locEnd,
       source,
     },
 
@@ -1138,7 +1135,7 @@ function toCST<T>(
       whitespaceStart: null,
       whitespaceEnd: null,
       locStart,
-      locEnd: locEndSecondToLast,
+      locEnd,
       source,
     },
 
@@ -1148,7 +1145,7 @@ function toCST<T>(
       whitespaceStart: null,
       whitespaceEnd: null,
       locStart,
-      locEnd: locEndSecondToLast,
+      locEnd,
       source,
     },
 
@@ -1166,7 +1163,7 @@ function toCST<T>(
       whitespaceStart: null,
       whitespaceEnd: null,
       locStart,
-      locEnd: locEndSecondToLast,
+      locEnd,
       source,
     },
 
@@ -1189,7 +1186,7 @@ function toCST<T>(
       delimiterWhitespaceStart: null,
       delimiterWhitespaceEnd: null,
       locStart,
-      locEnd: locEndSecondToLast,
+      locEnd,
       source,
       blockStartLocStart: (tokens: Node[]) => offset + tokens[0].source.startIdx,
       blockStartLocEnd: (tokens: Node[]) => offset + tokens[2].source.endIdx,
@@ -1239,7 +1236,7 @@ function toCST<T>(
       whitespaceStart: null,
       whitespaceEnd: null,
       locStart,
-      locEnd: locEndSecondToLast,
+      locEnd,
       source,
     },
   };

From df1a06ac315272e52aad2e4a5515ac27b2e6e8fa Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Fri, 26 Sep 2025 16:02:29 +0200
Subject: [PATCH 08/18] pld: more fixes due to arity changes

---
 packages/liquid-html-parser/src/stage-1-cst.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 2aa739871..2f44b4f77 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -750,8 +750,8 @@ function toCST<T>(
       type: ConcreteNodeTypes.ForMarkup,
       variableName: 0,
       collection: 4,
-      reversed: 6,
-      args: 8,
+      reversed: (children: Node[]) => children[5].children[1]?.sourceString ?? null,
+      args: 7,
       locStart,
       locEnd,
       source,
@@ -1459,7 +1459,7 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
       source,
       paramType: 2,
       paramName: 4,
-      paramDescription: 8,
+      paramDescription: 7,
     },
     descriptionNode: {
       type: ConcreteNodeTypes.LiquidDocDescriptionNode,

From 6db5d74d92829cad7f27be1d884ab929bf383059 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Fri, 26 Sep 2025 16:09:20 +0200
Subject: [PATCH 09/18] fix: access of `this`

---
 packages/liquid-html-parser/src/stage-1-cst.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 2f44b4f77..0f7607b3e 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -1469,8 +1469,8 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
       source,
       content: 2,
       isImplicit: false,
-      isInline: function (this: Node) {
-        return !this.children[1].sourceString.includes('\n');
+      isInline: function (children) {
+        return !children[1].sourceString.includes('\n');
       },
     },
     descriptionContent: textNode(),
@@ -1500,8 +1500,8 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
       locEnd,
       source,
       content: 2,
-      isInline: function (this: Node) {
-        return !this.children[1].sourceString.includes('\n');
+      isInline: function (children) {
+        return !children[1].sourceString.includes('\n');
       },
     },
     promptNode: {

From 90343708cef6e4830d4d6cec0e1a8c538f0a281c Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Fri, 26 Sep 2025 16:54:25 +0200
Subject: [PATCH 10/18] pld: fix up one more arity issue

---
 packages/liquid-html-parser/src/stage-1-cst.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 0f7607b3e..a8b6e735c 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -1303,7 +1303,7 @@ function toCST<T>(
     HtmlVoidElement: {
       type: ConcreteNodeTypes.HtmlVoidElement,
       name: 1,
-      attrList: 3,
+      attrList: 2,
       locStart,
       locEnd,
       source,

From 6d476b97a22de7273f1c929729b00cdd51775234 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Mon, 29 Sep 2025 11:22:28 +0200
Subject: [PATCH 11/18] pld: make sure MatchResults are properly used()

---
 packages/liquid-html-parser/src/stage-1-cst.ts | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index a8b6e735c..016434e0b 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -591,7 +591,9 @@ function toCST<T>(
 
   const res = grammar.match(matchingSource, 'Node');
   if (res.failed()) {
-    throw new LiquidHTMLCSTParsingError(res);
+    res.use(r => {
+      throw new LiquidHTMLCSTParsingError(r);
+    });
   }
 
   const HelperMappings: Mapping = {
@@ -1402,7 +1404,7 @@ function toCST<T>(
     }),
     {},
   );
-  return new AstBuilder(selectedMappings).toAst(res) as T;
+  return res.use(r => new AstBuilder(selectedMappings).toAst(r) as T);
 }
 
 /**
@@ -1418,7 +1420,9 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
 
   const res = LiquidDocGrammar.match(matchingSource, 'Node');
   if (res.failed()) {
-    throw new LiquidHTMLCSTParsingError(res);
+    res.use(r => {
+      throw new LiquidHTMLCSTParsingError(r);
+    });
   }
 
   /**
@@ -1517,5 +1521,5 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
     fallbackNode: textNode(),
   };
 
-  return toAST(res, LiquidDocMappings);
+  return res.use(r => new AstBuilder(LiquidDocMappings).toAst(r));
 }

From 5dd086fc3be6b5cec3b2b9147490d7156eefec88 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 8 Oct 2025 16:22:13 +0200
Subject: [PATCH 12/18] upgrade to latest version of @ohm-js/wasm

---
 packages/liquid-html-parser/package.json | 2 +-
 yarn.lock                                | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index 1fd84c2cc..c5e4ed8e0 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -32,7 +32,7 @@
     "type-check": "tsc --noEmit"
   },
   "dependencies": {
-    "@ohm-js/wasm": "^0.6.2",
+    "@ohm-js/wasm": "^0.6.5",
     "line-column": "^1.0.2",
     "ohm-js": "^17.0.0"
   },
diff --git a/yarn.lock b/yarn.lock
index 9f8939171..813fb0040 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -909,10 +909,10 @@
     "@nodelib/fs.scandir" "2.1.5"
     fastq "^1.6.0"
 
-"@ohm-js/wasm@^0.6.2":
-  version "0.6.2"
-  resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.2.tgz#a1c33a859cb62e2f87541f42a8a729b7a0b9aaa3"
-  integrity sha512-kWmF4oSa7r0t91xd36pzXPyGi0FQDmBHoTeY/VA2AMStvs+2iyQ1qnN01RjhbIfiza2v0YLXjDfmainCEHuPeA==
+"@ohm-js/wasm@^0.6.5":
+  version "0.6.5"
+  resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.5.tgz#9b924ca390f31cc6114e281fbc61a2667022ed6e"
+  integrity sha512-9V9UGFti7sMnUN5jjbGYW2Mqq8qsMYZnGRL3u4xvv18TQkQpAF9RTY5oovFEHPn1XweYjPmBKCvoPxbfZ5k5Ug==
   dependencies:
     "@wasmgroundup/emit" "^1.0.2"
 

From 51fae52637df15a6be4d6fd90a735665020e9a9c Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 8 Oct 2025 16:23:40 +0200
Subject: [PATCH 13/18] update imports

---
 packages/liquid-html-parser/src/errors.ts      | 2 +-
 packages/liquid-html-parser/src/stage-1-cst.ts | 8 ++------
 2 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/packages/liquid-html-parser/src/errors.ts b/packages/liquid-html-parser/src/errors.ts
index 254604455..5b4d67d2e 100644
--- a/packages/liquid-html-parser/src/errors.ts
+++ b/packages/liquid-html-parser/src/errors.ts
@@ -1,5 +1,5 @@
 import lineColumn from 'line-column';
-import { MatchResult } from 'ohm-js';
+import { MatchResult } from '@ohm-js/wasm';
 import { NodeTypes, Position } from './types';
 
 interface LineColPosition {
diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 016434e0b..887f52d0f 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -31,8 +31,8 @@
  */
 
 import { Parser } from 'prettier';
-import { Grammar, Node } from 'ohm-js';
-import { AstBuilder } from '@ohm-js/wasm';
+import { AstBuilder, CstNode as Node, AstMapping as Mapping } from '@ohm-js/wasm';
+import { Grammar } from '@ohm-js/wasm/compat';
 
 import {
   LiquidDocGrammar,
@@ -509,10 +509,6 @@ export type LiquidDocConcreteNode =
   | ConcreteLiquidDocDescriptionNode
   | ConcreteLiquidDocPromptNode;
 
-interface Mapping {
-  [k: string]: number | TemplateMapping | TopLevelFunctionMapping;
-}
-
 interface TemplateMapping {
   type: ConcreteNodeTypes;
   locStart: (node: Node[]) => number;

From 4cca53e8455a3922cac8387a7a4948e39cfa6522 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 8 Oct 2025 16:29:51 +0200
Subject: [PATCH 14/18] fix types

---
 .../liquid-html-parser/src/stage-1-cst.ts     | 28 +++++++++----------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 887f52d0f..9c8ccadfa 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -577,8 +577,8 @@ function toCST<T>(
 
   const textNode = {
     type: ConcreteNodeTypes.TextNode,
-    value: function () {
-      return this.currNode.sourceString;
+    value: function (this: AstBuilder<T>) {
+      return this.currNode!.sourceString;
     },
     locStart,
     locEnd,
@@ -587,12 +587,12 @@ function toCST<T>(
 
   const res = grammar.match(matchingSource, 'Node');
   if (res.failed()) {
-    res.use(r => {
+    res.use((r) => {
       throw new LiquidHTMLCSTParsingError(r);
     });
   }
 
-  const HelperMappings: Mapping = {
+  const HelperMappings: Mapping<T | null> = {
     Node: 0,
     TextNode: textNode,
     orderedListOf: 0,
@@ -604,7 +604,7 @@ function toCST<T>(
     },
   };
 
-  const LiquidMappings: Mapping = {
+  const LiquidMappings: Mapping<T | null | string> = {
     liquidNode: 0,
     liquidRawTag: 0,
     liquidRawTagImpl: {
@@ -1117,7 +1117,7 @@ function toCST<T>(
     tagMarkup: (n: Node) => n.sourceString.trim(),
   };
 
-  const LiquidStatement: Mapping = {
+  const LiquidStatement: Mapping<T> = {
     LiquidStatement: 0,
     liquidTagOpenRule: {
       type: ConcreteNodeTypes.LiquidTagOpen,
@@ -1239,9 +1239,9 @@ function toCST<T>(
     },
   };
 
-  const LiquidHTMLMappings: Mapping = {
+  const LiquidHTMLMappings: Mapping<T | T[]> = {
     Node(frontmatter: Node, nodes: Node) {
-      const frontmatterNode =
+      const frontmatterNode: T[] =
         frontmatter.sourceString.length === 0 ? [] : [this.toAst(frontmatter)];
 
       return frontmatterNode.concat(this.toAst(nodes));
@@ -1400,7 +1400,7 @@ function toCST<T>(
     }),
     {},
   );
-  return res.use(r => new AstBuilder(selectedMappings).toAst(r) as T);
+  return res.use((r) => new AstBuilder<T>(selectedMappings).toAst(r) as T);
 }
 
 /**
@@ -1416,7 +1416,7 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
 
   const res = LiquidDocGrammar.match(matchingSource, 'Node');
   if (res.failed()) {
-    res.use(r => {
+    res.use((r) => {
       throw new LiquidHTMLCSTParsingError(r);
     });
   }
@@ -1426,15 +1426,15 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
    */
   const textNode = () => ({
     type: ConcreteNodeTypes.TextNode,
-    value: function () {
-      return this.currNode.sourceString;
+    value: function (this: AstBuilder): string {
+      return this.currNode!.sourceString;
     },
     locStart,
     locEnd,
     source,
   });
 
-  const LiquidDocMappings: Mapping = {
+  const LiquidDocMappings: Mapping<LiquidDocConcreteNode | LiquidDocConcreteNode[]> = {
     Node(implicitDescription: Node, body: Node) {
       const implicitDescriptionNode =
         implicitDescription.sourceString.length === 0 ? [] : [this.toAst(implicitDescription)];
@@ -1517,5 +1517,5 @@ function toLiquidDocAST(source: string, matchingSource: string, offset: number)
     fallbackNode: textNode(),
   };
 
-  return res.use(r => new AstBuilder(LiquidDocMappings).toAst(r));
+  return res.use((r) => new AstBuilder(LiquidDocMappings).toAst(r));
 }

From d96801f72760bc887e2262dda4f9ca4b1b5a6eb3 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 8 Oct 2025 16:30:01 +0200
Subject: [PATCH 15/18] FIXME: ts-ignore last type error

---
 packages/liquid-html-parser/src/stage-1-cst.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 9c8ccadfa..07690ec58 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -998,6 +998,7 @@ function toCST<T>(
       source,
     },
 
+    // @ts-ignore
     liquidBooleanExpression(initialCondition: Node, subsequentConditions: Node) {
       const initialConditionAst = this.toAst(initialCondition) as ConcreteLiquidCondition;
       const subsequentConditionAsts = this.toAst(subsequentConditions) as ConcreteLiquidCondition[];

From 27dce6d54abd7975c6747ffd326c216d9daf71ae Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 8 Oct 2025 16:34:38 +0200
Subject: [PATCH 16/18] fix up build issues due to pure-ESM package

---
 packages/codemirror-language-client/tsconfig.json | 2 +-
 packages/lang-jsonc/tsconfig.json                 | 2 +-
 tsconfig.json                                     | 8 ++++----
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/codemirror-language-client/tsconfig.json b/packages/codemirror-language-client/tsconfig.json
index 48524f58b..d064ecbf8 100644
--- a/packages/codemirror-language-client/tsconfig.json
+++ b/packages/codemirror-language-client/tsconfig.json
@@ -6,6 +6,7 @@
     "outDir": "./dist/esm",
     "tsBuildInfoFile": "./dist/esm/tsconfig.tsbuildInfo",
     "module": "es6",
+    "moduleResolution": "node",
     "rootDir": "src",
     "resolveJsonModule": false,
     "lib": [
@@ -15,4 +16,3 @@
     ]
   }
 }
-
diff --git a/packages/lang-jsonc/tsconfig.json b/packages/lang-jsonc/tsconfig.json
index 48524f58b..d064ecbf8 100644
--- a/packages/lang-jsonc/tsconfig.json
+++ b/packages/lang-jsonc/tsconfig.json
@@ -6,6 +6,7 @@
     "outDir": "./dist/esm",
     "tsBuildInfoFile": "./dist/esm/tsconfig.tsbuildInfo",
     "module": "es6",
+    "moduleResolution": "node",
     "rootDir": "src",
     "resolveJsonModule": false,
     "lib": [
@@ -15,4 +16,3 @@
     ]
   }
 }
-
diff --git a/tsconfig.json b/tsconfig.json
index 2be1d643e..c17ef1956 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -9,9 +9,9 @@
     // "disableSolutionSearching": true,                 /* Opt a project out of multi-project reference checking when editing. */
     // "disableReferencedProjectLoad": true,             /* Reduce the number of projects loaded automatically by TypeScript. */
     /* Language and Environment */
-    "target": "es2019", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
+    "target": "es2020", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
     "lib": [
-      "es2019"
+      "es2020"
     ], /* Specify a set of bundled library declaration files that describe the target runtime environment. */
     // "jsx": "preserve",                                /* Specify what JSX code is generated. */
     // "experimentalDecorators": true,                   /* Enable experimental support for TC39 stage 2 draft decorators. */
@@ -24,9 +24,9 @@
     // "useDefineForClassFields": true,                  /* Emit ECMAScript-standard-compliant class fields. */
     // "moduleDetection": "auto",                        /* Control what method is used to detect module-format JS files. */
     /* Modules */
-    "module": "commonjs", /* Specify what module code is generated. */
+    "module": "node20", /* Specify what module code is generated. */
     "rootDir": ".", /* Specify the root folder within your source files. */
-    "moduleResolution": "node16", /* Specify how TypeScript looks up a file from a given module specifier. */
+    // "moduleResolution": "",                           /* Specify how TypeScript looks up a file from a given module specifier. */
     // "baseUrl": "./",                                  /* Specify the base directory to resolve non-relative module names. */
     "paths": {
       "@shopify/theme-check-common": [

From a99d8b8a476f1819ac046a473511117cf490b33f Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Wed, 8 Oct 2025 20:13:51 +0200
Subject: [PATCH 17/18] Use' using' to ensure MatchResults are properly
 disposed

---
 packages/liquid-html-parser/src/grammar.spec.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/liquid-html-parser/src/grammar.spec.ts b/packages/liquid-html-parser/src/grammar.spec.ts
index 01e08a8d0..0cb27eafb 100644
--- a/packages/liquid-html-parser/src/grammar.spec.ts
+++ b/packages/liquid-html-parser/src/grammar.spec.ts
@@ -101,7 +101,7 @@ describe('Unit: liquidHtmlGrammar', () => {
         expectMatchSucceeded('<6h>').to.be.false;
 
         function expectMatchSucceeded(text: string) {
-          const match = grammar.LiquidHTML.match(text, 'Node');
+          using match = grammar.LiquidHTML.match(text, 'Node');
           return expect(match.succeeded(), text);
         }
       });
@@ -129,7 +129,7 @@ describe('Unit: liquidHtmlGrammar', () => {
         `).to.be.true;
 
         function expectMatchSucceeded(text: string) {
-          const match = grammar.LiquidStatement.match(text.trimStart(), 'Node');
+          using match = grammar.LiquidStatement.match(text.trimStart(), 'Node');
           return expect(match.succeeded(), text);
         }
       });
@@ -156,7 +156,7 @@ describe('Unit: liquidHtmlGrammar', () => {
     });
 
     function expectMatchSucceeded(text: string) {
-      const match = placeholderGrammars.LiquidHTML.match(text.trimStart(), 'Node');
+      using match = placeholderGrammars.LiquidHTML.match(text.trimStart(), 'Node');
       return expect(match.succeeded(), text);
     }
   });

From b9def04b142fc103240c626bb6579f714fd2f255 Mon Sep 17 00:00:00 2001
From: Patrick Dubroy <pdubroy@gmail.com>
Date: Thu, 9 Oct 2025 11:31:40 +0200
Subject: [PATCH 18/18] use `when` for proper handling of Opt nodes

---
 packages/liquid-html-parser/package.json      |  2 +-
 .../liquid-html-parser/src/stage-1-cst.ts     | 46 +++++++++----------
 yarn.lock                                     |  8 ++--
 3 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/packages/liquid-html-parser/package.json b/packages/liquid-html-parser/package.json
index c5e4ed8e0..ac329fdfc 100644
--- a/packages/liquid-html-parser/package.json
+++ b/packages/liquid-html-parser/package.json
@@ -32,7 +32,7 @@
     "type-check": "tsc --noEmit"
   },
   "dependencies": {
-    "@ohm-js/wasm": "^0.6.5",
+    "@ohm-js/wasm": "^0.6.8",
     "line-column": "^1.0.2",
     "ohm-js": "^17.0.0"
   },
diff --git a/packages/liquid-html-parser/src/stage-1-cst.ts b/packages/liquid-html-parser/src/stage-1-cst.ts
index 07690ec58..1c65cd0e6 100644
--- a/packages/liquid-html-parser/src/stage-1-cst.ts
+++ b/packages/liquid-html-parser/src/stage-1-cst.ts
@@ -891,19 +891,12 @@ function toCST<T>(
       source,
     },
     renderArguments: 1,
-    completionModeRenderArguments: function (
-      _0,
-      namedArguments,
-      _2,
-      _3,
-      _4,
-      _5,
-      variableLookup,
-      _7,
-    ) {
-      // variableLookup.sourceString can be '' when there are no incomplete params
+    completionModeRenderArguments: function (_0, namedArguments, _2, _3, opt) {
       return this.toAst(namedArguments).concat(
-        variableLookup.sourceString === '' ? [] : this.toAst(variableLookup),
+        opt.when({
+          Some: (_sep, variableLookup, _space) => this.toAst(variableLookup),
+          None: () => [],
+        }),
       );
     },
     snippetExpression: 0,
@@ -954,29 +947,34 @@ function toCST<T>(
       locStart,
       locEnd,
       source,
-      args(nodes: Node[]) {
-        if (nodes[4].sourceString === '') {
-          // Traditionally, this would get transformed into null or array. But
-          // it's better if we have an empty array instead of null here.
-          return [];
-        }
-        const argumentsNode = nodes[4].children[3];
-        return this.toAst(argumentsNode);
+      args([_sp1, _bar, _sp2, ident, opt]: Node[]) {
+        // Traditionally, this would get transformed into null or array. But
+        // it's better if we have an empty array instead of null here.
+        return opt.when({
+          Some: (_sp1, _colon, _sp2, args, _opt) => this.toAst(args),
+          None: () => [],
+        });
       },
     },
     filterArguments: 0,
     arguments: 0,
-    complexArguments: function (completeParams, _space1, _comma, _space2, incompleteParam) {
+    complexArguments: function (completeParams, opt) {
       return this.toAst(completeParams).concat(
-        incompleteParam.sourceString === '' ? [] : this.toAst(incompleteParam),
+        opt.when({
+          Some: (_space1, _comma, _space2, incompleteParam) => this.toAst(incompleteParam),
+          None: () => [],
+        }),
       );
     },
     simpleArgument: 0,
     tagArguments: 0,
     contentForTagArgument: 0,
-    completionModeContentForTagArgument: function (namedArguments, _separator, variableLookup) {
+    completionModeContentForTagArgument: function (namedArguments, opt) {
       return this.toAst(namedArguments).concat(
-        variableLookup.sourceString === '' ? [] : this.toAst(variableLookup),
+        opt.when({
+          Some: (_sep, variableLookup) => this.toAst(variableLookup),
+          None: () => [],
+        }),
       );
     },
     positionalArgument: 0,
diff --git a/yarn.lock b/yarn.lock
index 813fb0040..5d78c08ff 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -909,10 +909,10 @@
     "@nodelib/fs.scandir" "2.1.5"
     fastq "^1.6.0"
 
-"@ohm-js/wasm@^0.6.5":
-  version "0.6.5"
-  resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.5.tgz#9b924ca390f31cc6114e281fbc61a2667022ed6e"
-  integrity sha512-9V9UGFti7sMnUN5jjbGYW2Mqq8qsMYZnGRL3u4xvv18TQkQpAF9RTY5oovFEHPn1XweYjPmBKCvoPxbfZ5k5Ug==
+"@ohm-js/wasm@^0.6.8":
+  version "0.6.8"
+  resolved "https://registry.yarnpkg.com/@ohm-js/wasm/-/wasm-0.6.8.tgz#9436eccee089dcfc4dd79bb493905abd4e7f96df"
+  integrity sha512-Z8zXCT8A9lTcMgTvLKjx2ZxDL67esf+9P0ymXWoCIBgIEtTswoluW4g/edjXE4WnjhTTQDbPc+bP7IXLgYfefg==
   dependencies:
     "@wasmgroundup/emit" "^1.0.2"