bug(#334): add three registry suggestions to --fix

Register node => fix builders in src/fixers.js for three declarative rules,
each a suggestion applied only under --fix-suggestions: output-method-xml
(switch method="xml" to "html"), missing-version-in-stylesheet (insert
version="1.0" after the element name), and mode-or-priority-without-match
(delete the orphan attribute when exactly one of mode/priority is present, else
leave the defect fix-less). The per-file linter now skips attaching a fix when
the builder returns null. No new linter or category move — a declarative rule
carries a fix through the registry.

Author: maxonfjvipon

CHANGELOG.md

@@ -9,6 +9,12 @@ publication date only; detailed notes begin with the Unreleased section.
 
 ## Unreleased
 
+- Add three more `--fix-suggestions`, each a `src/fixers.js` registry entry:
+  `output-method-xml` (switch `method="xml"` to `"html"`),
+  `missing-version-in-stylesheet` (declare `version="1.0"`), and
+  `mode-or-priority-without-match` (delete the orphan attribute, when exactly
+  one of `mode`/`priority` is present) (#334).
+
 - Add a suggestion tier to `--fix`. A fix marked `suggestion` is opinionated —
   it changes behavior, removes code, or is one of several valid corrections —
   so `--fix` leaves it and only the new `--fix-suggestions` applies it. A

CLAUDE.md

@@ -137,9 +137,9 @@ Configuration by users: a `.xslint.yml` file (discovered by walking up from the
 
 Command-line flags override the file; the file overrides the built-in defaults. Resolution lives in `src/config.js` (which also exposes the config's `base` directory); `src/xslint.js` expands each rule pattern against the check names, folds `off` rules into the suppression list, filters excluded files against `base`, applies severity overrides to the collected defects, and resolves the effective `max-warnings`/`log-level`/`quiet`.
 
-Fixing by users: `xslint --fix` rewrites the mechanically-fixable defects in place (`--fix-dry-run` reports the same result without writing any file). A defect is fixable when it carries a `fix: {line, col, value, replacement, suggestion?}` — `xpath-format-linter` attaches one to each `redundant-whitespace` defect, `xpath-axis-linter` to each `unabbreviated-axis` defect, `namespace-linter` to each `redundant-namespace-declarations` defect (its `value` is the reconstructed ` xmlns:prefix="uri"` text, so the verify step skips a single-quoted or oddly spaced declaration rather than deleting the wrong span), and `node-set-linter` to each `use-node-set-extension` defect (a single span from `prefix:node-set(` through its matching `)`, replaced by the inner argument). A *declarative* xpath rule can carry a fix too, without becoming a code-based linter: `src/fixers.js` maps a check name to a `node => fix` builder, and `xpath-linter` attaches the fix that builder returns to each defect it finds for that check — that is how `using-disable-output-escaping` gets its fix. Attribute-deleting fixes (the namespace declaration, the `disable-output-escaping` attribute) share `deletion(attribute)` in `src/fixes.js`. `src/fixer.js` maps each fix's position to a source offset and applies it *only* when the span still holds the exact `value` (a shifted offset — an entity ahead of the run, an already-edited file — is skipped, never corrupting the source), applying a file's fixes from the end backwards so earlier offsets stay valid, and returns the rewritten content per changed file plus the defects it applied. `src/xslint.js` writes the changed files (unless `--fix-dry-run`) and drops the applied defects from the report, so the exit code reflects only what remains.
+Fixing by users: `xslint --fix` rewrites the mechanically-fixable defects in place (`--fix-dry-run` reports the same result without writing any file). A defect is fixable when it carries a `fix: {line, col, value, replacement, suggestion?}` — `xpath-format-linter` attaches one to each `redundant-whitespace` defect, `xpath-axis-linter` to each `unabbreviated-axis` defect, `namespace-linter` to each `redundant-namespace-declarations` defect (its `value` is the reconstructed ` xmlns:prefix="uri"` text, so the verify step skips a single-quoted or oddly spaced declaration rather than deleting the wrong span), and `node-set-linter` to each `use-node-set-extension` defect (a single span from `prefix:node-set(` through its matching `)`, replaced by the inner argument). A *declarative* xpath rule can carry a fix too, without becoming a code-based linter: `src/fixers.js` maps a check name to a `node => fix` builder, and `xpath-linter` attaches the fix that builder returns to each defect it finds for that check (a builder returns null when it cannot resolve the defect with one edit, and the linter then leaves the defect fix-less). The registry drives four suggestions — `using-disable-output-escaping` and `mode-or-priority-without-match` (delete an attribute), `output-method-xml` (`method="xml"`→`"html"`), and `missing-version-in-stylesheet` (insert `version="1.0"` after the element name). Attribute-deleting fixes (the namespace declaration, the `disable-output-escaping` and orphan `mode`/`priority` attributes) share `deletion(attribute)` in `src/fixes.js`. `src/fixer.js` maps each fix's position to a source offset and applies it *only* when the span still holds the exact `value` (a shifted offset — an entity ahead of the run, an already-edited file — is skipped, never corrupting the source), applying a file's fixes from the end backwards so earlier offsets stay valid, and returns the rewritten content per changed file plus the defects it applied. `src/xslint.js` writes the changed files (unless `--fix-dry-run`) and drops the applied defects from the report, so the exit code reflects only what remains.
 
-Fixes come in two tiers, set by the `suggestion` flag on the `fix`. A plain fix is *safe* — deterministic and semantics-preserving — and `--fix` applies it. A fix with `suggestion: true` is *opinionated* — it changes behavior, removes code, or is one of several valid corrections — so `--fix` leaves it and only `--fix-suggestions` applies it (`fixer.js` takes a `suggestions` flag and gates on it). `using-disable-output-escaping` is the first suggestion: deleting the attribute changes how output is escaped. When neither flag is passed, `xslint.js` counts the fixable defects and logs how many `--fix` would fix and how many more `--fix-suggestions` would. The fix engine is check-agnostic — the `fix` shape is the whole contract — so a new fixer attaches a `fix` (marking it a suggestion when it should be opt-in) and needs no engine change; the structural fixes (removing an unused variable, merging nested `xsl:if`) wait on the full-fidelity parser (#228) for exact per-node source spans.
+Fixes come in two tiers, set by the `suggestion` flag on the `fix`. A plain fix is *safe* — deterministic and semantics-preserving — and `--fix` applies it. A fix with `suggestion: true` is *opinionated* — it changes behavior, removes code, or is one of several valid corrections — so `--fix` leaves it and only `--fix-suggestions` applies it (`fixer.js` takes a `suggestions` flag and gates on it). Every fix in `src/fixers.js` is a suggestion so far — deleting `disable-output-escaping` changes escaping, switching the output method changes serialization, the declared version is a guess, and dropping `mode`/`priority` is one of two corrections. When neither flag is passed, `xslint.js` counts the fixable defects and logs how many `--fix` would fix and how many more `--fix-suggestions` would. The fix engine is check-agnostic — the `fix` shape is the whole contract — so a new fixer attaches a `fix` (marking it a suggestion when it should be opt-in) and needs no engine change; the structural fixes (removing an unused variable, merging nested `xsl:if`) wait on the full-fidelity parser (#228) for exact per-node source spans.
 
 ## Keeping Docs in Sync
 
@@ -162,7 +162,7 @@ A change that leaves any of these describing the old behavior is not done.
 | `src/xsl-validator.js` | Builds the corpus from raw sources; reports each stylesheet that is not well-formed XML and leaves it out |
 | `src/xpath-validator.js` | Splits each corpus expression into the valid ones (kept for the expression linters) and the malformed ones (reported) |
 | `src/xpath-linter.js` | Loads `checks/xpath/*.yaml`, applies per-file XPath rules, and attaches any `src/fixers.js` fix to the defect |
-| `src/fixers.js` | Maps a declarative check name to a `node => fix` builder, so an xpath rule can carry a fix (e.g. the `using-disable-output-escaping` suggestion) |
+| `src/fixers.js` | Maps a declarative check name to a `node => fix` builder, so an xpath rule can carry a fix — the suggestions for `using-disable-output-escaping`, `output-method-xml`, `missing-version-in-stylesheet`, `mode-or-priority-without-match` |
 | `src/fixes.js` | Shared fix builders — `deletion(attribute)` reconstructs an attribute's ` name="value"` span for removal |
 | `src/corpus-linter.js` | Loads `checks/corpus/*.yaml`, applies cross-file rules over the corpus |
 | `src/xpath-axis-linter.js` | Tokenizes every XPath/pattern attribute in the corpus and flags each verbose axis (`unabbreviated-axis`) with a fix |

README.md

@@ -249,10 +249,20 @@ silently by `--fix`:
 xslint --fix-suggestions path/to/dir
 ```
 
-Today this covers `using-disable-output-escaping` — the attribute is removed,
-which changes how the output is escaped, so you opt in. Checks whose correction
-needs real judgment (a fresh name, a more specific path) stay report-only. A
-run without `--fix` reports how many defects each option would fix.
+Today this covers:
+
+- `using-disable-output-escaping` — the attribute is removed, which changes how
+  the output is escaped.
+- `output-method-xml` — `method="xml"` becomes `"html"` when the stylesheet
+  emits HTML.
+- `missing-version-in-stylesheet` — `version="1.0"` is declared (a guess you may
+  want to change).
+- `mode-or-priority-without-match` — the orphan `mode` or `priority` attribute
+  is removed.
+
+Checks whose correction needs real judgment (a fresh name, a more specific
+path) stay report-only. A run without `--fix` reports how many defects each
+option would fix.
 
 Pass `--fix-dry-run` to see what would remain after fixing, without writing any
 file:

src/fixers.js

@@ -7,8 +7,7 @@ const {deletion} = require('./fixes')
 
 /**
  * Fix for `using-disable-output-escaping`: delete the attribute. Removing it
- * changes how the output is escaped, so it is a suggestion — applied only under
- * `--fix-suggestions`, never silently by `--fix`.
+ * changes how the output is escaped, so it is a suggestion.
  * @param {Element} node - The element carrying the attribute
  * @return {object} - The suggestion fix
  */
@@ -19,14 +18,66 @@ const disableOutputEscaping = function(node) {
   }
 }
 
+/**
+ * Fix for `output-method-xml`: switch the method to `html`. It changes the
+ * serialization, so it is a suggestion.
+ * @param {Element} node - The `xsl:output` element
+ * @return {object} - The suggestion fix
+ */
+const outputMethodXml = function(node) {
+  const method = node.getAttributeNode('method')
+  return {
+    line: method.lineNumber,
+    col: method.columnNumber + 1,
+    value: 'xml',
+    replacement: 'html',
+    suggestion: true,
+  }
+}
+
+/**
+ * Fix for `missing-version-in-stylesheet`: declare `version="1.0"` right after
+ * the element name. The version is a guess, so it is a suggestion.
+ * @param {Element} node - The `xsl:stylesheet` element
+ * @return {object} - The suggestion fix
+ */
+const missingVersion = function(node) {
+  return {
+    line: node.lineNumber,
+    col: node.columnNumber + node.nodeName.length + 1,
+    value: '',
+    replacement: ' version="1.0"',
+    suggestion: true,
+  }
+}
+
+/**
+ * Fix for `mode-or-priority-without-match`: delete the orphan attribute. It is
+ * one of two corrections the rule offers (the other is adding `match`), so it
+ * is a suggestion, and only when exactly one of `mode`/`priority` is present
+ * can a single deletion resolve the defect — with both, there is no fix.
+ * @param {Element} node - The `xsl:template` element
+ * @return {?object} - The suggestion fix, or null
+ */
+const modeOrPriority = function(node) {
+  const present = ['mode', 'priority'].filter((name) => node.hasAttribute(name))
+  return present.length === 1 ?
+    {...deletion(node.getAttributeNode(present[0])), suggestion: true} :
+    null
+}
+
 /**
  * Fix builders for declarative Xpath checks, keyed by check name. The per-file
  * linter attaches the fix a builder returns to the defect it found for that
- * check, so a rule stays declarative while still carrying a fix.
- * @type {{[check: string]: function(Node): object}}
+ * check, so a rule stays declarative while still carrying a fix; a builder
+ * returns null when it cannot resolve the defect with a single edit.
+ * @type {{[check: string]: function(Node): ?object}}
  */
 const FIXERS = {
   'using-disable-output-escaping': disableOutputEscaping,
+  'output-method-xml': outputMethodXml,
+  'missing-version-in-stylesheet': missingVersion,
+  'mode-or-priority-without-match': modeOrPriority,
 }
 
 module.exports = {

src/xpath-linter.js

@@ -69,8 +69,9 @@ const lintByXpath = function(corpus, suppressions = []) {
           line: node.lineNumber,
           pos: node.columnNumber,
         }
-        if (FIXERS[pack.name]) {
-          defect.fix = FIXERS[pack.name](node)
+        const fix = FIXERS[pack.name] && FIXERS[pack.name](node)
+        if (fix) {
+          defect.fix = fix
         }
         defects.push(defect)
       }

test/fixer.test.js

@@ -101,6 +101,31 @@ describe('fixer', function() {
       fixture('using-disable-output-escaping.fixed.xsl'),
     )
   })
+  it('should switch an xml output method to html with --fix-suggestions',
+    function() {
+      const file = scratch(fixture('output-method-xml.xsl'))
+      runXslint(['--fix-suggestions', file])
+      assert.equal(
+        fs.readFileSync(file, 'utf-8'),
+        fixture('output-method-xml.fixed.xsl'),
+      )
+    })
+  it('should declare a missing version with --fix-suggestions', function() {
+    const file = scratch(fixture('missing-version-in-stylesheet.xsl'))
+    runXslint(['--fix-suggestions', file])
+    assert.equal(
+      fs.readFileSync(file, 'utf-8'),
+      fixture('missing-version-in-stylesheet.fixed.xsl'),
+    )
+  })
+  it('should drop an orphan mode with --fix-suggestions', function() {
+    const file = scratch(fixture('mode-or-priority-without-match.xsl'))
+    runXslint(['--fix-suggestions', file])
+    assert.equal(
+      fs.readFileSync(file, 'utf-8'),
+      fixture('mode-or-priority-without-match.fixed.xsl'),
+    )
+  })
   it('should announce how many defects --fix would fix', function() {
     const file = scratch(dirty)
     assert.ok(xslintStreams([file]).stderr.includes('fixable with --fix'))

test/resources/fix/missing-version-in-stylesheet.fixed.xsl

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+* SPDX-FileCopyrightText: Copyright (c) 2025-2026 Max Trunnikov
+* SPDX-License-Identifier: MIT
+-->
+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+  <xsl:template match="/">
+    <xsl:value-of select="."/>
+  </xsl:template>
+</xsl:stylesheet>

test/resources/fix/missing-version-in-stylesheet.xsl

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+* SPDX-FileCopyrightText: Copyright (c) 2025-2026 Max Trunnikov
+* SPDX-License-Identifier: MIT
+-->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+  <xsl:template match="/">
+    <xsl:value-of select="."/>
+  </xsl:template>
+</xsl:stylesheet>

test/resources/fix/mode-or-priority-without-match.fixed.xsl

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+* SPDX-FileCopyrightText: Copyright (c) 2025-2026 Max Trunnikov
+* SPDX-License-Identifier: MIT
+-->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
+  <xsl:template name="city">
+    <xsl:value-of select="."/>
+  </xsl:template>
+</xsl:stylesheet>

test/resources/fix/mode-or-priority-without-match.xsl

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+* SPDX-FileCopyrightText: Copyright (c) 2025-2026 Max Trunnikov
+* SPDX-License-Identifier: MIT
+-->
+<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
+  <xsl:template name="city" mode="Bryansk">
+    <xsl:value-of select="."/>
+  </xsl:template>
+</xsl:stylesheet>