Add rule YAML Title Alias

README.md

@@ -43,6 +43,7 @@ Documentation for all rules can be found in the [rules docs](https://github.com/
 - [insert-yaml-attributes](https://github.com/platers/obsidian-linter/blob/master/docs/rules.md#insert-yaml-attributes)
 - [yaml-timestamp](https://github.com/platers/obsidian-linter/blob/master/docs/rules.md#yaml-timestamp)
 - [yaml-title](https://github.com/platers/obsidian-linter/blob/master/docs/rules.md#yaml-title)
+- [yaml-title-alias](https://github.com/platers/obsidian-linter/blob/master/docs/rules.md#yaml-title-alias)
 - [escape-yaml-special-characters](https://github.com/platers/obsidian-linter/blob/master/docs/rules.md#escape-yaml-special-characters)
 
 ### Heading rules

docs/rules.md

@@ -229,6 +229,58 @@ title: Filename
 
 ```
 
+### YAML Title Alias
+
+Alias: `yaml-title-alias`
+
+Inserts the title of the file into the YAML frontmatter's aliases section. Gets the title from the first H1 or filename.
+
+Options:
+- YAML aliases new section style: The style of the newly created aliases YAML property
+	- Default: `Multi-line array`
+	- `Multi-line array`: ```aliases:\n  - Title```
+	- `Single-line array`: ```aliases: [Title]```
+	- `Single string`: ```aliases: Title```
+- YAML aliases new array style: The style of the aliases YAML property for newly created arrays
+	- Default: `Multi-line array`
+	- `Multi-line array`: ```aliases:\n  - Title```
+	- `Single-line array`: ```aliases: [Title]```
+
+Example: Adds a header with the title from heading.
+
+Before:
+
+```markdown
+# Obsidian
+```
+
+After:
+
+```markdown
+---
+aliases:
+  - Obsidian # linter-yaml-title-alias
+---
+# Obsidian
+```
+Example: Adds a header with the title.
+
+Before:
+
+```markdown
+
+```
+
+After:
+
+```markdown
+---
+aliases:
+  - Filename # linter-yaml-title-alias
+---
+
+```
+
 ### Escape YAML Special Characters
 
 Alias: `escape-yaml-special-characters`

src/rules.ts

@@ -10,11 +10,12 @@ import {
   loadYAML,
   moveFootnotesToEnd,
   yamlRegex,
-  escapeYamlString,
+  toYamlString,
   makeEmphasisOrBoldConsistent,
   addTwoSpacesAtEndOfLinesFollowedByAnotherLineOfTextContent,
   makeSureThereIsOnlyOneBlankLineBeforeAndAfterParagraphs,
   removeSpacesInLinkText,
+  toSingleLineArrayYamlString,
 } from './utils';
 import {
   Option,
@@ -1606,7 +1607,7 @@ export const rules: Rule[] = [
         });
         title = title || options['metadata: file name'];
 
-        title = escapeYamlString(title);
+        title = toYamlString(title);
 
         return formatYAML(text, (text) => {
           const title_match_str = `\n${options['Title Key']}.*\n`;
@@ -1658,6 +1659,168 @@ export const rules: Rule[] = [
       [new TextOption('Title Key', 'Which YAML key to use for title', 'title')],
   ),
 
+  new Rule(
+      'YAML Title Alias',
+      'Inserts the title of the file into the YAML frontmatter\'s aliases section. Gets the title from the first H1 or filename.',
+      RuleType.YAML,
+      (text: string, options = {}) => {
+        text = initYAML(text);
+        let title = ignoreCodeBlocksYAMLTagsAndLinks(text, (text) => {
+          const result = text.match(/^#\s+(.*)/m);
+          if (result) {
+            return result[1];
+          }
+          return '';
+        });
+        title = title || options['metadata: file name'];
+
+        let yaml = text.match(yamlRegex)[1];
+        const aliasesRegex = /(?<=^|\n)aliases:[ \t]*(\S.*|(?:\n {2}\S.*)+)\n(?=$|\S)/;
+        let aliasesMatch = yaml.match(aliasesRegex);
+
+        const linterMarkerComment = '# linter-yaml-title-alias';
+
+        if (!aliasesMatch) {
+          let emptyValue;
+          switch (options['YAML aliases new section style']) {
+            case 'Multi-line array':
+              emptyValue = '\n  - \'\'';
+              break;
+            case 'Single-line array':
+              emptyValue = ' [\'\']';
+              break;
+            case 'Single string':
+              emptyValue = ' \'\'';
+              break;
+            default:
+              throw new Error(`Unsupported setting 'YAML aliases new section style': ${options['YAML aliases new section style']}`);
+          }
+
+          const newAliasesSection = `aliases:${emptyValue} ${linterMarkerComment}\n`;
+          let newYaml = yaml.replace(/(?<=^|\n)aliases:\s*/, newAliasesSection);
+
+          if (newYaml === yaml) {
+            newYaml = `${newAliasesSection}${yaml}`;
+          }
+
+          text = text.replace(`---\n${yaml}---`, `---\n${newYaml}---`);
+          yaml = newYaml;
+          aliasesMatch = yaml.match(aliasesRegex);
+        }
+
+        const aliasesValue = aliasesMatch[1];
+
+        const hasLinterMarkerComment = aliasesValue.includes(linterMarkerComment);
+
+        const isMultiline = aliasesValue.includes('\n');
+        const parsedAliases = loadYAML(aliasesValue);
+
+        const isSingleString = !isMultiline && aliasesValue.match(/^\[.*\]/) === null;
+
+        let resultAliasesArray = isSingleString ? [parsedAliases] : [...parsedAliases];
+
+        if (hasLinterMarkerComment) {
+          resultAliasesArray[0] = title;
+        } else {
+          resultAliasesArray = [title, ...resultAliasesArray];
+        }
+
+        const resultStyle = isSingleString ? (hasLinterMarkerComment ? 'Single string' : options['YAML aliases new array style']) : (isMultiline ? 'Multi-line array' : 'Single-line array');
+
+        let newAliasesYaml;
+
+        switch (resultStyle) {
+          case 'Multi-line array': {
+            const tailArrayYaml = resultAliasesArray.length === 1 ? '' : `\n${toYamlString(resultAliasesArray.slice(1))}`.replace(/\n-/g, '\n  -');
+            newAliasesYaml = `\n  - ${toYamlString(resultAliasesArray[0])} ${linterMarkerComment}${tailArrayYaml}`;
+            break;
+          }
+          case 'Single-line array':
+            newAliasesYaml = ` ${toSingleLineArrayYamlString(resultAliasesArray)} ${linterMarkerComment}`;
+            break;
+          case 'Single string':
+            newAliasesYaml = ` ${toYamlString(resultAliasesArray[0])} ${linterMarkerComment}`;
+            break;
+          default:
+            throw new Error(`Unsupported resultStyle: ${resultStyle}`);
+        }
+
+        text = text.replace(aliasesMatch[0], `aliases:${newAliasesYaml}\n`);
+
+        return text;
+      },
+      [
+        new Example(
+            'Adds a header with the title from heading.',
+            dedent`
+      # Obsidian
+      `,
+            dedent`
+      ---
+      aliases:
+        - Obsidian # linter-yaml-title-alias
+      ---
+      # Obsidian
+      `,
+            {
+              'YAML aliases new section style': 'Multi-line array',
+            },
+        ),
+        new Example(
+            'Adds a header with the title.',
+            dedent`
+      `,
+            dedent`
+      ---
+      aliases:
+        - Filename # linter-yaml-title-alias
+      ---
+
+      `,
+            {
+              'metadata: file name': 'Filename',
+              'YAML aliases new section style': 'Multi-line array',
+            },
+        ),
+      ],
+      [
+        new DropdownOption(
+            'YAML aliases new section style',
+            'The style of the newly created aliases YAML property',
+            'Multi-line array',
+            [
+              new DropdownRecord(
+                  'Multi-line array',
+                  '```aliases:\\n  - Title```',
+              ),
+              new DropdownRecord(
+                  'Single-line array',
+                  '```aliases: [Title]```',
+              ),
+              new DropdownRecord(
+                  'Single string',
+                  '```aliases: Title```',
+              ),
+            ],
+        ),
+        new DropdownOption(
+            'YAML aliases new array style',
+            'The style of the aliases YAML property for newly created arrays',
+            'Multi-line array',
+            [
+              new DropdownRecord(
+                  'Multi-line array',
+                  '```aliases:\\n  - Title```',
+              ),
+              new DropdownRecord(
+                  'Single-line array',
+                  '```aliases: [Title]```',
+              ),
+            ],
+        ),
+      ],
+  ),
+
   new Rule(
       'Escape YAML Special Characters',
       'Escapes colons with a space after them (: ), single quotes (\'), and double quotes (") in YAML.',