From 2b9439c6ca130d32540fe8a665d06e53bb82ceb7 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Wed, 23 Jul 2025 10:23:16 -0700
Subject: [PATCH 1/8] Update for TS7

I am testing Typescript 7's JS support, which I've largely rewritten
during the switch to Go. The new code doesn't support old,
Closure-derived syntax, such as uninitialised class property
declarations, which VFileMessage uses.

I made the smallest syntactic change to fix this, which is to initialise
all the optional properties declared this way with `undefined`. The
other two ways I thought of are:

1. Declare these properties as class properties in the body of the
class. This splits the properties up in a non-obvious way though.
2. Declare an interface type in a separate .d.ts file and merge that with VFileMessage so
Typescript thinks they are there without changing the runtime shape of
VFileMessage. I can't think of the JS syntax to make this merge happen,
though.

Other options are:

3. Do nothing, don't update to TS7.
4. Switch to .ts, add a build step to strip types.

I don't know how VFileMessage is used; having a consistent runtime shape
by virtue of using class property declarations or initialising all
properties to undefined generally means: faster performance, but more
memory usage. I suspect it doesn't matter because people aren't creating
millions of these objects per second, but I don't really know.

Because TS7 is quite a way off, I don't know whether you'll want to take
this PR. I created it to see how hard it would be to update popular JS
code that uses TS for checking.
---
 lib/index.js | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index c7676df..bcffea5 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -158,7 +158,6 @@ export class VFileMessage extends Error {
         ? options.place.start
         : options.place
 
-    /* eslint-disable no-unused-expressions */
     /**
      * Stack of ancestor nodes surrounding the message.
      *
@@ -196,7 +195,7 @@ export class VFileMessage extends Error {
      *
      * @type {string | undefined}
      */
-    this.file
+    this.file = undefined
 
     // Field from `Error`.
     /**
@@ -274,21 +273,21 @@ export class VFileMessage extends Error {
      *
      * @type {string | undefined}
      */
-    this.actual
+    this.actual = undefined
 
     /**
      * Suggest acceptable values that can be used instead of `actual`.
      *
      * @type {Array<string> | undefined}
      */
-    this.expected
+    this.expected = undefined
 
     /**
      * Long form description of the message (you should use markdown).
      *
      * @type {string | undefined}
      */
-    this.note
+    this.note = undefined
 
     /**
      * Link to docs for the message.
@@ -298,8 +297,7 @@ export class VFileMessage extends Error {
      *
      * @type {string | undefined}
      */
-    this.url
-    /* eslint-enable no-unused-expressions */
+    this.url = undefined
   }
 }
 

From 6fcabaf799f83cd44a1546293d6df0b51cf6e276 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Wed, 23 Jul 2025 11:32:37 -0700
Subject: [PATCH 2/8] Use interface merging to provide properties

---
 lib/index.js         | 29 -----------------------------
 tsconfig.json        |  3 ++-
 tsconfig.tsbuildinfo |  1 +
 types.d.ts           | 22 ++++++++++++++++++++++
 4 files changed, 25 insertions(+), 30 deletions(-)
 create mode 100644 tsconfig.tsbuildinfo
 create mode 100644 types.d.ts

diff --git a/lib/index.js b/lib/index.js
index bcffea5..0bef7bf 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -190,13 +190,6 @@ export class VFileMessage extends Error {
      */
     this.fatal = undefined
 
-    /**
-     * Path of a file (used throughout the `VFile` ecosystem).
-     *
-     * @type {string | undefined}
-     */
-    this.file = undefined
-
     // Field from `Error`.
     /**
      * Reason for message.
@@ -267,28 +260,6 @@ export class VFileMessage extends Error {
     // Not standard.
     // Feel free to add other non-standard fields to your messages.
 
-    /**
-     * Specify the source value that’s being reported, which is deemed
-     * incorrect.
-     *
-     * @type {string | undefined}
-     */
-    this.actual = undefined
-
-    /**
-     * Suggest acceptable values that can be used instead of `actual`.
-     *
-     * @type {Array<string> | undefined}
-     */
-    this.expected = undefined
-
-    /**
-     * Long form description of the message (you should use markdown).
-     *
-     * @type {string | undefined}
-     */
-    this.note = undefined
-
     /**
      * Link to docs for the message.
      *
diff --git a/tsconfig.json b/tsconfig.json
index 82cc749..fba7f22 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     "checkJs": true,
+    "noEmit": true,
     "customConditions": ["development"],
     "declaration": true,
     "emitDeclarationOnly": true,
@@ -11,5 +12,5 @@
     "target": "es2022"
   },
   "exclude": ["coverage/", "node_modules/"],
-  "include": ["**/*.js"]
+  "include": ["**/*.js", "types.d.ts"]
 }
diff --git a/tsconfig.tsbuildinfo b/tsconfig.tsbuildinfo
new file mode 100644
index 0000000..fa1a8ea
--- /dev/null
+++ b/tsconfig.tsbuildinfo
@@ -0,0 +1 @@
+{"root":["./index.js","./test.js","./lib/index.js","./types.d.ts"],"version":"5.8.3"}
\ No newline at end of file
diff --git a/types.d.ts b/types.d.ts
new file mode 100644
index 0000000..f41f116
--- /dev/null
+++ b/types.d.ts
@@ -0,0 +1,22 @@
+interface Error {
+  /**
+   * Path of a file (used throughout the `VFile` ecosystem).
+   */
+  file?: string
+
+  /**
+   * Specify the source value that's being reported, which is deemed
+   * incorrect.
+   */
+  actual?: unknown
+
+  /**
+   * Suggest acceptable values that can be used instead of `actual`.
+   */
+  expected?: unknown
+
+  /**
+   * Long form description of the message (you should use markdown).
+   */
+  note?: string
+}

From 47c5c01c898fd8c3555d4ffab06f4a6ed2b22a83 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Wed, 23 Jul 2025 11:48:20 -0700
Subject: [PATCH 3/8] also move url

---
 lib/index.js | 14 --------------
 types.d.ts   | 11 +++++++++++
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index 0bef7bf..2eb3b19 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -255,20 +255,6 @@ export class VFileMessage extends Error {
       legacyCause && options.cause && typeof options.cause.stack === 'string'
         ? options.cause.stack
         : ''
-
-    // The following fields are “well known”.
-    // Not standard.
-    // Feel free to add other non-standard fields to your messages.
-
-    /**
-     * Link to docs for the message.
-     *
-     * > 👉 **Note**: this must be an absolute URL that can be passed as `x`
-     * > to `new URL(x)`.
-     *
-     * @type {string | undefined}
-     */
-    this.url = undefined
   }
 }
 
diff --git a/types.d.ts b/types.d.ts
index f41f116..3250484 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -1,4 +1,7 @@
 interface Error {
+  // The following fields are “well known”.
+  // Not standard.
+  // Feel free to add other non-standard fields to your messages.
   /**
    * Path of a file (used throughout the `VFile` ecosystem).
    */
@@ -19,4 +22,12 @@ interface Error {
    * Long form description of the message (you should use markdown).
    */
   note?: string
+
+  /**
+   * Link to docs for the message.
+   *
+   * > 👉 **Note**: this must be an absolute URL that can be passed as `x`
+   * > to `new URL(x)`.
+   */
+  url?: string
 }

From cfb75277168a0acf0a6dd1b15e3de0232b64e82e Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Wed, 23 Jul 2025 11:48:53 -0700
Subject: [PATCH 4/8] remove tsbuildinfo

---
 tsconfig.tsbuildinfo | 1 -
 1 file changed, 1 deletion(-)
 delete mode 100644 tsconfig.tsbuildinfo

diff --git a/tsconfig.tsbuildinfo b/tsconfig.tsbuildinfo
deleted file mode 100644
index fa1a8ea..0000000
--- a/tsconfig.tsbuildinfo
+++ /dev/null
@@ -1 +0,0 @@
-{"root":["./index.js","./test.js","./lib/index.js","./types.d.ts"],"version":"5.8.3"}
\ No newline at end of file

From c31de17dc038fb19e4c94850d39269a74773df9a Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Thu, 24 Jul 2025 06:48:13 -0700
Subject: [PATCH 5/8] Revert "remove tsbuildinfo"

This reverts commit cfb75277168a0acf0a6dd1b15e3de0232b64e82e.
---
 tsconfig.tsbuildinfo | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 tsconfig.tsbuildinfo

diff --git a/tsconfig.tsbuildinfo b/tsconfig.tsbuildinfo
new file mode 100644
index 0000000..fa1a8ea
--- /dev/null
+++ b/tsconfig.tsbuildinfo
@@ -0,0 +1 @@
+{"root":["./index.js","./test.js","./lib/index.js","./types.d.ts"],"version":"5.8.3"}
\ No newline at end of file

From b36a4b9aafdfd7d3486fe2c3f675b665a3d5c7f8 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Thu, 24 Jul 2025 06:48:31 -0700
Subject: [PATCH 6/8] Revert "also move url"

This reverts commit 47c5c01c898fd8c3555d4ffab06f4a6ed2b22a83.
---
 lib/index.js | 14 ++++++++++++++
 types.d.ts   | 11 -----------
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/lib/index.js b/lib/index.js
index 2eb3b19..0bef7bf 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -255,6 +255,20 @@ export class VFileMessage extends Error {
       legacyCause && options.cause && typeof options.cause.stack === 'string'
         ? options.cause.stack
         : ''
+
+    // The following fields are “well known”.
+    // Not standard.
+    // Feel free to add other non-standard fields to your messages.
+
+    /**
+     * Link to docs for the message.
+     *
+     * > 👉 **Note**: this must be an absolute URL that can be passed as `x`
+     * > to `new URL(x)`.
+     *
+     * @type {string | undefined}
+     */
+    this.url = undefined
   }
 }
 
diff --git a/types.d.ts b/types.d.ts
index 3250484..f41f116 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -1,7 +1,4 @@
 interface Error {
-  // The following fields are “well known”.
-  // Not standard.
-  // Feel free to add other non-standard fields to your messages.
   /**
    * Path of a file (used throughout the `VFile` ecosystem).
    */
@@ -22,12 +19,4 @@ interface Error {
    * Long form description of the message (you should use markdown).
    */
   note?: string
-
-  /**
-   * Link to docs for the message.
-   *
-   * > 👉 **Note**: this must be an absolute URL that can be passed as `x`
-   * > to `new URL(x)`.
-   */
-  url?: string
 }

From 0f7a65e839f3fea2873c0fb112c27ea332c36c56 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Thu, 24 Jul 2025 06:48:43 -0700
Subject: [PATCH 7/8] Revert "Use interface merging to provide properties"

This reverts commit 6fcabaf799f83cd44a1546293d6df0b51cf6e276.
---
 lib/index.js         | 29 +++++++++++++++++++++++++++++
 tsconfig.json        |  3 +--
 tsconfig.tsbuildinfo |  1 -
 types.d.ts           | 22 ----------------------
 4 files changed, 30 insertions(+), 25 deletions(-)
 delete mode 100644 tsconfig.tsbuildinfo
 delete mode 100644 types.d.ts

diff --git a/lib/index.js b/lib/index.js
index 0bef7bf..bcffea5 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -190,6 +190,13 @@ export class VFileMessage extends Error {
      */
     this.fatal = undefined
 
+    /**
+     * Path of a file (used throughout the `VFile` ecosystem).
+     *
+     * @type {string | undefined}
+     */
+    this.file = undefined
+
     // Field from `Error`.
     /**
      * Reason for message.
@@ -260,6 +267,28 @@ export class VFileMessage extends Error {
     // Not standard.
     // Feel free to add other non-standard fields to your messages.
 
+    /**
+     * Specify the source value that’s being reported, which is deemed
+     * incorrect.
+     *
+     * @type {string | undefined}
+     */
+    this.actual = undefined
+
+    /**
+     * Suggest acceptable values that can be used instead of `actual`.
+     *
+     * @type {Array<string> | undefined}
+     */
+    this.expected = undefined
+
+    /**
+     * Long form description of the message (you should use markdown).
+     *
+     * @type {string | undefined}
+     */
+    this.note = undefined
+
     /**
      * Link to docs for the message.
      *
diff --git a/tsconfig.json b/tsconfig.json
index fba7f22..82cc749 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,7 +1,6 @@
 {
   "compilerOptions": {
     "checkJs": true,
-    "noEmit": true,
     "customConditions": ["development"],
     "declaration": true,
     "emitDeclarationOnly": true,
@@ -12,5 +11,5 @@
     "target": "es2022"
   },
   "exclude": ["coverage/", "node_modules/"],
-  "include": ["**/*.js", "types.d.ts"]
+  "include": ["**/*.js"]
 }
diff --git a/tsconfig.tsbuildinfo b/tsconfig.tsbuildinfo
deleted file mode 100644
index fa1a8ea..0000000
--- a/tsconfig.tsbuildinfo
+++ /dev/null
@@ -1 +0,0 @@
-{"root":["./index.js","./test.js","./lib/index.js","./types.d.ts"],"version":"5.8.3"}
\ No newline at end of file
diff --git a/types.d.ts b/types.d.ts
deleted file mode 100644
index f41f116..0000000
--- a/types.d.ts
+++ /dev/null
@@ -1,22 +0,0 @@
-interface Error {
-  /**
-   * Path of a file (used throughout the `VFile` ecosystem).
-   */
-  file?: string
-
-  /**
-   * Specify the source value that's being reported, which is deemed
-   * incorrect.
-   */
-  actual?: unknown
-
-  /**
-   * Suggest acceptable values that can be used instead of `actual`.
-   */
-  expected?: unknown
-
-  /**
-   * Long form description of the message (you should use markdown).
-   */
-  note?: string
-}

From 62e8a8b32924416c191ac049ca29d98f63c56950 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Thu, 24 Jul 2025 06:51:44 -0700
Subject: [PATCH 8/8] correct default value for VFileMessage.file

---
 lib/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/index.js b/lib/index.js
index bcffea5..e6b54a3 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -195,7 +195,7 @@ export class VFileMessage extends Error {
      *
      * @type {string | undefined}
      */
-    this.file = undefined
+    this.file = ''
 
     // Field from `Error`.
     /**