From 9325f8d2b1e1647031d1327e7fbfd38f6b6e666b Mon Sep 17 00:00:00 2001
From: andyexeter <palmer.andy@gmail.com>
Date: Fri, 6 Mar 2026 12:11:37 +0000
Subject: [PATCH] Rename liquidSingleQuote option to twigSingleQuote

---
 playground/assets/playground.js               |  2 +-
 playground/index.html                         |  6 +-
 src/index.ts                                  | 12 ++-
 src/printer/print/liquid.ts                   | 15 ++--
 src/printer/printer-liquid-html.ts            |  4 +-
 src/printer/utils/string.ts                   |  8 +-
 src/types.ts                                  |  3 +-
 src/utils.ts                                  | 31 +++++++
 test/liquid-drop-string/fixed.liquid          |  2 +-
 test/liquid-drop-string/index.liquid          |  2 +-
 test/liquid-drop-variable-lookup/fixed.liquid |  2 +-
 test/liquid-drop-variable-lookup/index.liquid |  2 +-
 test/liquid-tag-form/fixed.liquid             |  4 +-
 test/liquid-tag-form/index.liquid             |  4 +-
 test/twig-function-quotes/fixed.liquid        |  8 +-
 test/twig-function-quotes/index.liquid        |  8 +-
 test/utils.spec.ts                            | 81 +++++++++++++++++++
 17 files changed, 159 insertions(+), 35 deletions(-)
 create mode 100644 test/utils.spec.ts

diff --git a/playground/assets/playground.js b/playground/assets/playground.js
index 9d345f3d..2b31aecc 100644
--- a/playground/assets/playground.js
+++ b/playground/assets/playground.js
@@ -3,7 +3,7 @@ const options = {
 };
 
 const numInputs = ['printWidth'];
-const boolInputs = ['liquidSingleQuote', 'singleQuote'];
+const boolInputs = ['twigSingleQuote', 'singleQuote'];
 const selectInputs = ['htmlWhitespaceSensitivity'];
 
 const waitFor = (pred) => {
diff --git a/playground/index.html b/playground/index.html
index c8f54f45..9e8fb248 100644
--- a/playground/index.html
+++ b/playground/index.html
@@ -107,9 +107,9 @@ <h1>
             <label title="Use single quotes instead of double quotes.">
               <input id="singleQuote" type="checkbox" /> --single-quote
             </label>
-            <label title="Use single quotes in Liquid.">
-              <input id="liquidSingleQuote" type="checkbox" checked />
-              --liquid-single-quote
+            <label title="Use single quotes in Twig.">
+              <input id="twigSingleQuote" type="checkbox" checked />
+              --twig-single-quote
             </label>
           </details>
         </div>
diff --git a/src/index.ts b/src/index.ts
index 5b1d29ff..c26e742d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -15,12 +15,20 @@ const languages: SupportLanguage[] = [
 ];
 
 const options: SupportOptions = {
-  liquidSingleQuote: {
+  twigSingleQuote: {
     type: 'boolean',
     category: 'LIQUID',
     default: true,
     description:
-      'Use single quotes instead of double quotes in Liquid tags and objects.',
+      'Use single quotes instead of double quotes in Twig tags and objects.',
+    since: '0.2.0',
+  },
+  liquidSingleQuote: {
+    type: 'boolean',
+    category: 'LIQUID',
+    default: undefined,
+    description:
+      'Deprecated: Use twigSingleQuote instead. Use single quotes instead of double quotes in Twig tags and objects.',
     since: '0.2.0',
   },
   embeddedSingleQuote: {
diff --git a/src/printer/print/liquid.ts b/src/printer/print/liquid.ts
index 008a2f87..67fc1401 100644
--- a/src/printer/print/liquid.ts
+++ b/src/printer/print/liquid.ts
@@ -16,7 +16,7 @@ import {
   LiquidStatement,
 } from '~/types';
 import { isBranchedTag } from '~/parser/stage-2-ast';
-import { assertNever } from '~/utils';
+import { assertNever, getTwigSingleQuote } from '~/utils';
 
 import {
   getWhitespaceTrim,
@@ -76,8 +76,11 @@ export function printLiquidDrop(
     ]);
   }
 
-  // Transform quotes in base case markup based on liquidSingleQuote option
-  const markup = transformStringQuotes(node.markup, options.liquidSingleQuote);
+  // Transform quotes in base case markup based on twigSingleQuote option
+  const markup = transformStringQuotes(
+    node.markup,
+    getTwigSingleQuote(options),
+  );
 
   // This should probably be better than this but it'll do for now.
   const lines = markupLines(markup);
@@ -271,7 +274,7 @@ function printLiquidStatement(
   const node = path.getValue();
   const transformedMarkup = transformStringQuotes(
     node.markup,
-    options.liquidSingleQuote,
+    getTwigSingleQuote(options),
   );
   const shouldSkipLeadingSpace =
     transformedMarkup.trim() === '' ||
@@ -349,10 +352,10 @@ export function printLiquidBlockStart(
     ]);
   }
 
-  // Transform quotes in base case markup based on liquidSingleQuote option
+  // Transform quotes in base case markup based on twigSingleQuote option
   const transformedMarkup = transformStringQuotes(
     node.markup,
-    options.liquidSingleQuote,
+    getTwigSingleQuote(options),
   );
   const lines = markupLines(transformedMarkup);
 
diff --git a/src/printer/printer-liquid-html.ts b/src/printer/printer-liquid-html.ts
index f2db0058..82386596 100644
--- a/src/printer/printer-liquid-html.ts
+++ b/src/printer/printer-liquid-html.ts
@@ -29,7 +29,7 @@ import {
   nonTraversableProperties,
   AstPath,
 } from '~/types';
-import { assertNever } from '~/utils';
+import { assertNever, getTwigSingleQuote } from '~/utils';
 
 import { preprocess } from '~/printer/print-preprocess';
 import {
@@ -524,7 +524,7 @@ function printNode(
     }
 
     case NodeTypes.String: {
-      const preferredQuote = options.liquidSingleQuote ? `'` : `"`;
+      const preferredQuote = getTwigSingleQuote(options) ? `'` : `"`;
       const valueHasQuotes = node.value.includes(preferredQuote);
       const quote = valueHasQuotes
         ? oppositeQuotes[preferredQuote]
diff --git a/src/printer/utils/string.ts b/src/printer/utils/string.ts
index b0db58c1..33bb21de 100644
--- a/src/printer/utils/string.ts
+++ b/src/printer/utils/string.ts
@@ -67,7 +67,7 @@ export function hasMoreThanOneNewLineBetweenNodes(
 }
 
 /**
- * Transforms quotes in base case markup strings based on the liquidSingleQuote option.
+ * Transforms quotes in base case markup strings based on the twigSingleQuote option.
  * This handles cases where the parser falls back to storing markup as a raw string
  * (e.g., Twig function calls like `stimulus_controller('controller-name')`).
  *
@@ -78,13 +78,13 @@ export function hasMoreThanOneNewLineBetweenNodes(
  */
 export function transformStringQuotes(
   markup: string,
-  liquidSingleQuote: boolean,
+  twigSingleQuote: boolean,
 ): string {
-  const preferredQuote = liquidSingleQuote ? "'" : '"';
+  const preferredQuote = twigSingleQuote ? "'" : '"';
 
   // Match strings with the non-preferred quote style
   // This regex matches quoted strings, being careful about escapes
-  const stringRegex = liquidSingleQuote
+  const stringRegex = twigSingleQuote
     ? /"([^"\\]|\\.)*"/g // Match double-quoted strings
     : /'([^'\\]|\\.)*'/g; // Match single-quoted strings
 
diff --git a/src/types.ts b/src/types.ts
index 70c0b260..abccbc8f 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -124,7 +124,8 @@ export type LiquidAstPath = AstPath<LiquidHtmlNode>;
 export type LiquidParserOptions = ParserOptions<LiquidHtmlNode> & {
   singleAttributePerLine: boolean;
   singleLineLinkTags: boolean;
-  liquidSingleQuote: boolean;
+  twigSingleQuote: boolean;
+  liquidSingleQuote?: boolean;
   embeddedSingleQuote: boolean;
   indentSchema: boolean;
 };
diff --git a/src/utils.ts b/src/utils.ts
index e0e69829..cc510c38 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -26,3 +26,34 @@ export function dropLast<T>(n: number, xs: readonly T[]) {
   }
   return result;
 }
+
+let hasWarnedLiquidSingleQuote = false;
+
+/**
+ * Resets the deprecation warning state. Only used for testing.
+ * @internal
+ */
+export function resetTwigSingleQuoteWarning(): void {
+  hasWarnedLiquidSingleQuote = false;
+}
+
+/**
+ * Gets the effective twigSingleQuote value, supporting the deprecated liquidSingleQuote option.
+ * Shows a deprecation warning once if liquidSingleQuote is used.
+ */
+export function getTwigSingleQuote(options: {
+  twigSingleQuote: boolean;
+  liquidSingleQuote?: boolean;
+}): boolean {
+  // If liquidSingleQuote is explicitly set (not undefined), use it with deprecation warning
+  if (options.liquidSingleQuote !== undefined) {
+    if (!hasWarnedLiquidSingleQuote) {
+      hasWarnedLiquidSingleQuote = true;
+      console.warn(
+        '[prettier-plugin-twig] The "liquidSingleQuote" option is deprecated. Please use "twigSingleQuote" instead.',
+      );
+    }
+    return options.liquidSingleQuote;
+  }
+  return options.twigSingleQuote;
+}
diff --git a/test/liquid-drop-string/fixed.liquid b/test/liquid-drop-string/fixed.liquid
index fd210519..824005a4 100644
--- a/test/liquid-drop-string/fixed.liquid
+++ b/test/liquid-drop-string/fixed.liquid
@@ -5,5 +5,5 @@ It should keep double quotes if the string includes single quotes
 {{ "string o' string" }}
 
 It should maintain whitespace stripping characters and respect the singleQuote config
-liquidSingleQuote: false
+twigSingleQuote: false
 {{- "hello" -}}
diff --git a/test/liquid-drop-string/index.liquid b/test/liquid-drop-string/index.liquid
index c72c91ba..968338ff 100644
--- a/test/liquid-drop-string/index.liquid
+++ b/test/liquid-drop-string/index.liquid
@@ -5,5 +5,5 @@ It should keep double quotes if the string includes single quotes
 {{ "string o' string" }}
 
 It should maintain whitespace stripping characters and respect the singleQuote config
-liquidSingleQuote: false
+twigSingleQuote: false
 {{- 'hello' -}}
diff --git a/test/liquid-drop-variable-lookup/fixed.liquid b/test/liquid-drop-variable-lookup/fixed.liquid
index 493c93f9..b7cfc3db 100644
--- a/test/liquid-drop-variable-lookup/fixed.liquid
+++ b/test/liquid-drop-variable-lookup/fixed.liquid
@@ -24,7 +24,7 @@ It should index access strings with spaces
 {{ x.y['hello world'] }}
 
 It should respect singleQuote
-liquidSingleQuote: false
+twigSingleQuote: false
 {{ x.y["hello world"] }}
 
 It should keep double quotes if single quotes are in the string
diff --git a/test/liquid-drop-variable-lookup/index.liquid b/test/liquid-drop-variable-lookup/index.liquid
index d68f1801..3eb9d927 100644
--- a/test/liquid-drop-variable-lookup/index.liquid
+++ b/test/liquid-drop-variable-lookup/index.liquid
@@ -24,7 +24,7 @@ It should index access strings with spaces
 {{ x["y"]["hello world"] }}
 
 It should respect singleQuote
-liquidSingleQuote: false
+twigSingleQuote: false
 {{ x["y"]["hello world"] }}
 
 It should keep double quotes if single quotes are in the string
diff --git a/test/liquid-tag-form/fixed.liquid b/test/liquid-tag-form/fixed.liquid
index dcf6a37a..e3a5c901 100644
--- a/test/liquid-tag-form/fixed.liquid
+++ b/test/liquid-tag-form/fixed.liquid
@@ -5,13 +5,13 @@ printWidth: 1
   hello
 {% endform %}
 
-It can take named arguments, and respects liquidSingleQuote
+It can take named arguments, and respects twigSingleQuote
 printWidth: 1
 {% form 'cart',
   key: value
 %}{% endform %}
 
-It can take named arguments, and respects liquidSingleQuote (pw80)
+It can take named arguments, and respects twigSingleQuote (pw80)
 printWidth: 80
 {% form 'cart', key1: value1, key2: 'value2' %}{% endform %}
 
diff --git a/test/liquid-tag-form/index.liquid b/test/liquid-tag-form/index.liquid
index 2b2d1c16..2007320e 100644
--- a/test/liquid-tag-form/index.liquid
+++ b/test/liquid-tag-form/index.liquid
@@ -3,11 +3,11 @@ printWidth: 1
 {% form x %}{% endform %}
 {% form x %}hello{% endform %}
 
-It can take named arguments, and respects liquidSingleQuote
+It can take named arguments, and respects twigSingleQuote
 printWidth: 1
 {% form "cart",key:value%}{% endform %}
 
-It can take named arguments, and respects liquidSingleQuote (pw80)
+It can take named arguments, and respects twigSingleQuote (pw80)
 printWidth: 80
 {% form "cart",key1:value1, key2:'value2' %} {% endform %}
 
diff --git a/test/twig-function-quotes/fixed.liquid b/test/twig-function-quotes/fixed.liquid
index ec244957..47b641d6 100644
--- a/test/twig-function-quotes/fixed.liquid
+++ b/test/twig-function-quotes/fixed.liquid
@@ -11,12 +11,12 @@ It should convert double quotes to single quotes in tag base case
 It should handle multiple arguments with quotes
 {{ some_function('arg1', 'arg2') }}
 
-It should convert to double quotes when liquidSingleQuote is false
-liquidSingleQuote: false
+It should convert to double quotes when twigSingleQuote is false
+twigSingleQuote: false
 {{ stimulus_controller("controller-name") }}
 
-It should keep single quotes if string contains double quotes when liquidSingleQuote is false
-liquidSingleQuote: false
+It should keep single quotes if string contains double quotes when twigSingleQuote is false
+twigSingleQuote: false
 {{ stimulus_controller('say "hello"') }}
 
 It should not modify HTML attributes within Twig comments
diff --git a/test/twig-function-quotes/index.liquid b/test/twig-function-quotes/index.liquid
index 0972ccd2..2d11c1bb 100644
--- a/test/twig-function-quotes/index.liquid
+++ b/test/twig-function-quotes/index.liquid
@@ -11,12 +11,12 @@ It should convert double quotes to single quotes in tag base case
 It should handle multiple arguments with quotes
 {{ some_function("arg1", "arg2") }}
 
-It should convert to double quotes when liquidSingleQuote is false
-liquidSingleQuote: false
+It should convert to double quotes when twigSingleQuote is false
+twigSingleQuote: false
 {{ stimulus_controller('controller-name') }}
 
-It should keep single quotes if string contains double quotes when liquidSingleQuote is false
-liquidSingleQuote: false
+It should keep single quotes if string contains double quotes when twigSingleQuote is false
+twigSingleQuote: false
 {{ stimulus_controller('say "hello"') }}
 
 It should not modify HTML attributes within Twig comments
diff --git a/test/utils.spec.ts b/test/utils.spec.ts
new file mode 100644
index 00000000..fee78373
--- /dev/null
+++ b/test/utils.spec.ts
@@ -0,0 +1,81 @@
+import { expect } from 'chai';
+import { getTwigSingleQuote, resetTwigSingleQuoteWarning } from 'src/utils';
+
+describe('Module: utils', () => {
+  describe('Unit: getTwigSingleQuote', () => {
+    let warnCalls: string[];
+    let originalWarn: typeof console.warn;
+
+    beforeEach(() => {
+      warnCalls = [];
+      originalWarn = console.warn;
+      console.warn = (message: string) => {
+        warnCalls.push(message);
+      };
+      // Reset the warning state before each test
+      resetTwigSingleQuoteWarning();
+    });
+
+    afterEach(() => {
+      console.warn = originalWarn;
+    });
+
+    it('should return twigSingleQuote when liquidSingleQuote is not set', () => {
+      expect(getTwigSingleQuote({ twigSingleQuote: true })).to.equal(true);
+      expect(getTwigSingleQuote({ twigSingleQuote: false })).to.equal(false);
+      expect(warnCalls.length).to.equal(0);
+    });
+
+    it('should return twigSingleQuote when liquidSingleQuote is undefined', () => {
+      expect(getTwigSingleQuote({ twigSingleQuote: true, liquidSingleQuote: undefined })).to.equal(
+        true,
+      );
+      expect(getTwigSingleQuote({ twigSingleQuote: false, liquidSingleQuote: undefined })).to.equal(
+        false,
+      );
+      expect(warnCalls.length).to.equal(0);
+    });
+
+    it('should return liquidSingleQuote when it is explicitly set', () => {
+      expect(getTwigSingleQuote({ twigSingleQuote: true, liquidSingleQuote: false })).to.equal(
+        false,
+      );
+
+      resetTwigSingleQuoteWarning();
+
+      expect(getTwigSingleQuote({ twigSingleQuote: false, liquidSingleQuote: true })).to.equal(
+        true,
+      );
+    });
+
+    it('should show deprecation warning when liquidSingleQuote is explicitly set', () => {
+      getTwigSingleQuote({ twigSingleQuote: true, liquidSingleQuote: false });
+
+      expect(warnCalls.length).to.equal(1);
+      expect(warnCalls[0]).to.include('liquidSingleQuote');
+      expect(warnCalls[0]).to.include('deprecated');
+      expect(warnCalls[0]).to.include('twigSingleQuote');
+    });
+
+    it('should only show deprecation warning once per session', () => {
+      getTwigSingleQuote({ twigSingleQuote: true, liquidSingleQuote: false });
+      getTwigSingleQuote({ twigSingleQuote: true, liquidSingleQuote: false });
+      getTwigSingleQuote({ twigSingleQuote: false, liquidSingleQuote: true });
+
+      expect(warnCalls.length).to.equal(1);
+    });
+
+    it('should prefer liquidSingleQuote over twigSingleQuote for backwards compatibility', () => {
+      // When both are set, liquidSingleQuote should win
+      expect(getTwigSingleQuote({ twigSingleQuote: true, liquidSingleQuote: false })).to.equal(
+        false,
+      );
+
+      resetTwigSingleQuoteWarning();
+
+      expect(getTwigSingleQuote({ twigSingleQuote: false, liquidSingleQuote: true })).to.equal(
+        true,
+      );
+    });
+  });
+});