From dc665b01d47ccbd5de5cd22ee39ac9e162ec63bc Mon Sep 17 00:00:00 2001
From: Kevin Gibbons <bakkot@gmail.com>
Date: Sun, 29 Jan 2023 18:24:50 -0800
Subject: [PATCH 1/3] slightly more precise types for format nodes

---
 src/node-types.ts |  8 ++++----
 src/parser.ts     | 11 +++++++++--
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/node-types.ts b/src/node-types.ts
index cf2000a..17bbed4 100644
--- a/src/node-types.ts
+++ b/src/node-types.ts
@@ -137,25 +137,25 @@ export type TextNode = {
 
 export type StarNode = {
   name: 'star';
-  contents: FragmentNode[];
+  contents: (TextNode | CommentNode | TagNode)[];
   location: LocationRange;
 };
 
 export type UnderscoreNode = {
   name: 'underscore';
-  contents: FragmentNode[];
+  contents: [TextNode];
   location: LocationRange;
 };
 
 export type TickNode = {
   name: 'tick';
-  contents: FragmentNode[];
+  contents: (TextNode | CommentNode | TagNode)[];
   location: LocationRange;
 };
 
 export type TildeNode = {
   name: 'tilde';
-  contents: FragmentNode[];
+  contents: (TextNode | CommentNode | TagNode)[];
   location: LocationRange;
 };
 
diff --git a/src/parser.ts b/src/parser.ts
index 5ba5065..8771ebc 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -20,6 +20,7 @@ import type {
   OrderedListNode,
   OrderedListItemNode,
   UnorderedListItemNode,
+  FormatNode,
 } from './node-types';
 
 // TODO types for escapeHtml
@@ -283,11 +284,14 @@ export class Parser {
     return this.finish({ name: 'text', contents }, undefined, endLoc);
   }
 
-  parseFormat(format: Format, opts: ParseFragmentOpts) {
+  parseFormat(
+    format: Format,
+    opts: ParseFragmentOpts
+  ): (TextNode | CommentNode | TagNode | FormatNode)[] {
     const startTok = this._t.next() as FormatToken;
     let contents: (TextNode | CommentNode | TagNode)[] = [];
 
-    if (startTok.name === 'underscore') {
+    if (format === 'underscore') {
       if (this._t.peek().name === 'text') {
         contents = [this._t.next() as TextNode];
       }
@@ -336,6 +340,9 @@ export class Parser {
       } else {
         return [this.finish(ntNode, start, end)];
       }
+    } else if (format === 'underscore') {
+      // the cast is justified by the check at the start of this function
+      return [this.finish({ name: format, contents: contents as [TextNode] }, start, end)];
     }
 
     return [this.finish({ name: format, contents }, start, end)];

From 9d2bf8cdd7ab118faa3915c7a99ed42f7da94832 Mon Sep 17 00:00:00 2001
From: Kevin Gibbons <bakkot@gmail.com>
Date: Sun, 29 Jan 2023 18:32:04 -0800
Subject: [PATCH 2/3] even more precise type for underscore nodes

---
 src/emitter.ts    |  2 +-
 src/node-types.ts |  2 +-
 src/parser.ts     | 10 ++++++++--
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/emitter.ts b/src/emitter.ts
index 0301f34..11d313a 100644
--- a/src/emitter.ts
+++ b/src/emitter.ts
@@ -122,7 +122,7 @@ export class Emitter {
   }
 
   emitUnderscore(node: UnderscoreNode) {
-    this.wrapFragment('var', node.contents);
+    this.str += `<var>${node.contents}</var>`;
   }
 
   emitTag(tag: OpaqueTagNode | CommentNode | TagNode) {
diff --git a/src/node-types.ts b/src/node-types.ts
index 17bbed4..253a8f8 100644
--- a/src/node-types.ts
+++ b/src/node-types.ts
@@ -143,7 +143,7 @@ export type StarNode = {
 
 export type UnderscoreNode = {
   name: 'underscore';
-  contents: [TextNode];
+  contents: string;
   location: LocationRange;
 };
 
diff --git a/src/parser.ts b/src/parser.ts
index 8771ebc..7a109d6 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -341,8 +341,14 @@ export class Parser {
         return [this.finish(ntNode, start, end)];
       }
     } else if (format === 'underscore') {
-      // the cast is justified by the check at the start of this function
-      return [this.finish({ name: format, contents: contents as [TextNode] }, start, end)];
+      return [
+        this.finish(
+          // the cast is justified by the check at the start of this function
+          { name: 'underscore', contents: (contents as [TextNode])[0].contents },
+          start,
+          end
+        ),
+      ];
     }
 
     return [this.finish({ name: format, contents }, start, end)];

From 13542fef00a8982b2c2e57e9bb6ca2fc6b5c570f Mon Sep 17 00:00:00 2001
From: Kevin Gibbons <bakkot@gmail.com>
Date: Tue, 31 Jan 2023 08:15:54 -0800
Subject: [PATCH 3/3] fix visitor

---
 src/visitor.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/visitor.ts b/src/visitor.ts
index edb49d9..0ccca49 100644
--- a/src/visitor.ts
+++ b/src/visitor.ts
@@ -7,7 +7,7 @@ const childKeys = {
   algorithm: ['contents'],
   text: [],
   star: ['contents'],
-  underscore: ['contents'],
+  underscore: [],
   tick: ['contents'],
   tilde: ['contents'],
   pipe: [],