From b141df541708f74fe6f7b0c9a3d38aee5239f7f9 Mon Sep 17 00:00:00 2001
From: Oleksii Shmalko <rasen.dubi@gmail.com>
Date: Sun, 19 May 2024 03:47:51 +0300
Subject: [PATCH] feat: support export-snippet

---
 .changeset/nine-jeans-pay.md                  | 12 +++++
 .../src/__snapshots__/parser.spec.ts.snap     | 48 +++++++++++++++++++
 packages/uniorg-parse/src/parser.spec.ts      |  8 ++++
 packages/uniorg-parse/src/parser.ts           | 23 +++++++++
 .../__snapshots__/org-to-hast.spec.ts.snap    |  6 +++
 .../uniorg-rehype/src/org-to-hast.spec.ts     |  2 +
 packages/uniorg-rehype/src/org-to-hast.ts     |  5 ++
 .../src/__snapshots__/stringify.spec.ts.snap  |  5 ++
 .../uniorg-stringify/src/stringify.spec.ts    |  2 +
 packages/uniorg-stringify/src/stringify.ts    |  4 +-
 packages/uniorg/src/index.ts                  |  7 +++
 11 files changed, 121 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/nine-jeans-pay.md

diff --git a/.changeset/nine-jeans-pay.md b/.changeset/nine-jeans-pay.md
new file mode 100644
index 0000000..b891a06
--- /dev/null
+++ b/.changeset/nine-jeans-pay.md
@@ -0,0 +1,12 @@
+---
+'uniorg-parse': major
+'uniorg-stringify': minor
+'uniorg-rehype': minor
+'uniorg': minor
+---
+
+Support `export-snippet` in uniorg, uniorg-parse, uniorg-rehype, and uniorg-stringify.
+
+`export-snippet` has the following form: `@@backend:value@@`. Example: `@@html:<b>@@some text@@html:</b>`.
+
+This is a breaking change for uniorg-parse as it may output nodes unknown to downstream users (uniorg-rehype and uniorg-stringify). If you upgrade uniorg-parse, you should also upgrade uniorg-rehype and uniorg-stringify to the corresponding versions.
diff --git a/packages/uniorg-parse/src/__snapshots__/parser.spec.ts.snap b/packages/uniorg-parse/src/__snapshots__/parser.spec.ts.snap
index 71ec1bf..0021453 100644
--- a/packages/uniorg-parse/src/__snapshots__/parser.spec.ts.snap
+++ b/packages/uniorg-parse/src/__snapshots__/parser.spec.ts.snap
@@ -1280,6 +1280,54 @@ children:
         value: ")"
 `;
 
+exports[`org/parser export-snippet fake export snippet, missing backend 1`] = `
+type: "org-data"
+contentsBegin: 0
+contentsEnd: 7
+children:
+  - type: "paragraph"
+    affiliated: {}
+    contentsBegin: 0
+    contentsEnd: 7
+    children:
+      - type: "text"
+        value: "@@<b>@@"
+`;
+
+exports[`org/parser export-snippet html export snippet 1`] = `
+type: "org-data"
+contentsBegin: 0
+contentsEnd: 38
+children:
+  - type: "paragraph"
+    affiliated: {}
+    contentsBegin: 0
+    contentsEnd: 38
+    children:
+      - type: "export-snippet"
+        backEnd: "html"
+        value: "<b>"
+      - type: "text"
+        value: "hello, world!"
+      - type: "export-snippet"
+        backEnd: "html"
+        value: "</b>"
+`;
+
+exports[`org/parser export-snippet incomplete export snippet 1`] = `
+type: "org-data"
+contentsBegin: 0
+contentsEnd: 27
+children:
+  - type: "paragraph"
+    affiliated: {}
+    contentsBegin: 0
+    contentsEnd: 27
+    children:
+      - type: "text"
+        value: "@@html:fake export snippet@"
+`;
+
 exports[`org/parser fake keyword 1`] = `
 type: "org-data"
 contentsBegin: 0
diff --git a/packages/uniorg-parse/src/parser.spec.ts b/packages/uniorg-parse/src/parser.spec.ts
index 5f41d27..837b8aa 100644
--- a/packages/uniorg-parse/src/parser.spec.ts
+++ b/packages/uniorg-parse/src/parser.spec.ts
@@ -1098,4 +1098,12 @@ more text
 
     itParses('reference suffix', `[cite:@hello p.13]`);
   });
+
+  describe('export-snippet', () => {
+    itParses('html export snippet', '@@html:<b>@@hello, world!@@html:</b>@@');
+
+    itParses('incomplete export snippet', '@@html:fake export snippet@');
+
+    itParses('fake export snippet, missing backend', '@@<b>@@');
+  });
 });
diff --git a/packages/uniorg-parse/src/parser.ts b/packages/uniorg-parse/src/parser.ts
index 4e93e3a..b281ced 100644
--- a/packages/uniorg-parse/src/parser.ts
+++ b/packages/uniorg-parse/src/parser.ts
@@ -52,6 +52,7 @@ import {
   CitationKey,
   CitationSuffix,
   CitationCommonSuffix,
+  ExportSnippet,
 } from 'uniorg';
 
 import { getOrgEntity } from './entities.js';
@@ -611,6 +612,11 @@ class Parser {
           return this.parseStrikeThrough();
         }
         break;
+      case '@':
+        if (restriction.has('export-snippet')) {
+          return this.parseExportSnippet();
+        }
+        break;
       case '$':
         if (restriction.has('latex-fragment')) {
           return this.parseLatexFragment();
@@ -1630,6 +1636,23 @@ class Parser {
     return u('entity', { useBrackets: hasBrackets, ...value });
   }
 
+  private parseExportSnippet(): ExportSnippet | null {
+    const m = this.r.advance(this.r.lookingAt(/@@([-A-Za-z0-9]+):/));
+    if (!m) return null;
+
+    const backEnd = m[1];
+    const contentsBegin = this.r.offset();
+
+    const mend = this.r.advance(this.r.match(/@@/));
+    if (!mend) return null;
+
+    const contentsEnd = this.r.offset() - 2; // exclude @@
+
+    const value = this.r.substring(contentsBegin, contentsEnd);
+
+    return u('export-snippet', { backEnd, value });
+  }
+
   private parseLatexFragment(): LatexFragment | null {
     const begin = this.r.offset();
     const prefix = this.r.peek(2);
diff --git a/packages/uniorg-rehype/src/__snapshots__/org-to-hast.spec.ts.snap b/packages/uniorg-rehype/src/__snapshots__/org-to-hast.spec.ts.snap
index ce23f9a..72305c0 100644
--- a/packages/uniorg-rehype/src/__snapshots__/org-to-hast.spec.ts.snap
+++ b/packages/uniorg-rehype/src/__snapshots__/org-to-hast.spec.ts.snap
@@ -183,6 +183,12 @@ exports[`org/org-to-hast export html keyword 1`] = `
 
 `;
 
+exports[`org/org-to-hast export snippet 1`] = `
+
+<p><b>Hello, world!</b></p>
+
+`;
+
 exports[`org/org-to-hast fixed-width 1`] = `
 
 <pre class="fixed-width">hello</pre>
diff --git a/packages/uniorg-rehype/src/org-to-hast.spec.ts b/packages/uniorg-rehype/src/org-to-hast.spec.ts
index 67c1c0d..5fee29b 100644
--- a/packages/uniorg-rehype/src/org-to-hast.spec.ts
+++ b/packages/uniorg-rehype/src/org-to-hast.spec.ts
@@ -260,6 +260,8 @@ export
 #+HTML: <h1>html tag</h1>`
   );
 
+  hastTest('export snippet', `@@html:<b>@@Hello, world!@@html:</b>@@`);
+
   hastTest(
     'special block',
     `#+begin_blah
diff --git a/packages/uniorg-rehype/src/org-to-hast.ts b/packages/uniorg-rehype/src/org-to-hast.ts
index bd73b4e..765f5ed 100644
--- a/packages/uniorg-rehype/src/org-to-hast.ts
+++ b/packages/uniorg-rehype/src/org-to-hast.ts
@@ -79,6 +79,11 @@ const defaultHandlers: Handlers = {
   'citation-key': function (org) {
     return this.h(org, 'a', { href: 'cite:' + org.key }, ['cite:' + org.key]);
   },
+
+  'export-snippet': function (org) {
+    if (org.backEnd !== 'html') return null;
+    return u('raw', org.value) as any;
+  },
 };
 
 function renderAsChildren(
diff --git a/packages/uniorg-stringify/src/__snapshots__/stringify.spec.ts.snap b/packages/uniorg-stringify/src/__snapshots__/stringify.spec.ts.snap
index d452422..10d4eef 100644
--- a/packages/uniorg-stringify/src/__snapshots__/stringify.spec.ts.snap
+++ b/packages/uniorg-stringify/src/__snapshots__/stringify.spec.ts.snap
@@ -211,6 +211,11 @@ exports[`stringify footnotes starting on next line 1`] = `
 "
 `;
 
+exports[`stringify handle export-snippet 1`] = `
+"@@backend:custom value@@
+"
+`;
+
 exports[`stringify handlers allow handlers to return empty string to suppress output 1`] = `
 "hello,  world
 "
diff --git a/packages/uniorg-stringify/src/stringify.spec.ts b/packages/uniorg-stringify/src/stringify.spec.ts
index 1a70f46..e971ea7 100644
--- a/packages/uniorg-stringify/src/stringify.spec.ts
+++ b/packages/uniorg-stringify/src/stringify.spec.ts
@@ -512,4 +512,6 @@ some text
       { handlers: { 'strike-through': () => null } }
     );
   });
+
+  test('handle export-snippet', `@@backend:custom value@@`);
 });
diff --git a/packages/uniorg-stringify/src/stringify.ts b/packages/uniorg-stringify/src/stringify.ts
index 1ff7ea3..93a1b31 100644
--- a/packages/uniorg-stringify/src/stringify.ts
+++ b/packages/uniorg-stringify/src/stringify.ts
@@ -16,7 +16,9 @@ export type StringifyOptions = {
 };
 
 const defaultOptions: StringifyOptions = {
-  handlers: {},
+  handlers: {
+    'export-snippet': (org) => `@@${org.backEnd}:${org.value}@@`,
+  },
 };
 
 function normalizeOptions(
diff --git a/packages/uniorg/src/index.ts b/packages/uniorg/src/index.ts
index eaaf316..665bc12 100644
--- a/packages/uniorg/src/index.ts
+++ b/packages/uniorg/src/index.ts
@@ -76,6 +76,7 @@ export type ObjectType =
   | FootnoteReference
   | LatexFragment
   | Entity
+  | ExportSnippet
   | TableCell;
 
 export type OrgNode = GreaterElementType | ElementType | ObjectType;
@@ -190,6 +191,12 @@ export interface Entity extends Node {
   utf8: string;
 }
 
+export interface ExportSnippet extends Node {
+  type: 'export-snippet';
+  backEnd: string;
+  value: string;
+}
+
 export interface List extends GreaterElement {
   type: 'plain-list';
   listType: 'ordered' | 'unordered' | 'descriptive';