refactor: early conditions first

src/index.js

@@ -7,7 +7,7 @@ const {
   filterTokens,
   convertHeadingToHTMLFragment,
   getMarkdownHeadings,
-  getMarkdownAnchorHTMLFragments,
+  getMarkdownIdOrAnchorNameFragments,
 } = require("./utils.js")
 
 /** @typedef {import('markdownlint').Rule} MarkdownLintRule */
@@ -46,13 +46,20 @@ const customRule = {
           }
         }
 
-        if (hrefSrc != null) {
+        if (hrefSrc == null) {
+          continue
+        }
+
         const url = new URL(hrefSrc, pathToFileURL(params.name))
         const isRelative =
           url.protocol === "file:" &&
           !hrefSrc.startsWith("/") &&
           !hrefSrc.startsWith("#")
-          if (isRelative) {
+
+        if (!isRelative) {
+          continue
+        }
+
         const detail = `"${hrefSrc}"`
 
         if (!fs.existsSync(url)) {
@@ -63,29 +70,42 @@ const customRule = {
           continue
         }
 
+        if (url.hash.length <= 0) {
+          if (hrefSrc.includes("#")) {
             if (type !== "link_open") {
+              onError({
+                lineNumber,
+                detail: `${detail} should not have a fragment identifier as it is an image`,
+              })
               continue
             }
 
-            if (url.hash.length <= 0) {
-              if (hrefSrc.includes("#")) {
             onError({
               lineNumber,
               detail: `${detail} should have a valid fragment identifier`,
             })
+            continue
           }
+          continue
+        }
+
+        if (type !== "link_open") {
+          onError({
+            lineNumber,
+            detail: `${detail} should not have a fragment identifier as it is an image`,
+          })
+          continue
         }
 
-            if (url.hash.length > 0) {
         const fileContent = fs.readFileSync(url, { encoding: "utf8" })
         const headings = getMarkdownHeadings(fileContent)
-              const anchorHTMLFragments =
-                getMarkdownAnchorHTMLFragments(fileContent)
+        const idOrAnchorNameHTMLFragments =
+          getMarkdownIdOrAnchorNameFragments(fileContent)
 
         /** @type {Map<string, number>} */
         const fragments = new Map()
 
-              const headingsHTMLFragments = headings.map((heading) => {
+        const fragmentsHTML = headings.map((heading) => {
           const fragment = convertHeadingToHTMLFragment(heading)
           const count = fragments.get(fragment) ?? 0
           fragments.set(fragment, count + 1)
@@ -95,16 +115,14 @@ const customRule = {
           return fragment
         })
 
-              headingsHTMLFragments.push(...anchorHTMLFragments)
+        fragmentsHTML.push(...idOrAnchorNameHTMLFragments)
 
-              if (!headingsHTMLFragments.includes(url.hash)) {
+        if (!fragmentsHTML.includes(url.hash)) {
           onError({
             lineNumber,
             detail: `${detail} should have a valid fragment identifier`,
           })
-              }
-            }
-          }
+          continue
         }
       }
     })

src/utils.js

@@ -119,7 +119,7 @@ const getMarkdownIdOrAnchorNameFragments = (content) => {
     }
 
     const anchorIdOrName = anchorMatch[1]
-    if (anchorIdOrName === undefined) {
+    if (anchorIdOrName.length <= 0) {
       continue
     }
 
@@ -136,5 +136,5 @@ module.exports = {
   filterTokens,
   convertHeadingToHTMLFragment,
   getMarkdownHeadings,
-  getMarkdownAnchorHTMLFragments: getMarkdownIdOrAnchorNameFragments,
+  getMarkdownIdOrAnchorNameFragments,
 }

test/utils.test.js

@@ -4,7 +4,7 @@ const assert = require("node:assert/strict")
 const {
   convertHeadingToHTMLFragment,
   getMarkdownHeadings,
-  getMarkdownAnchorHTMLFragments,
+  getMarkdownIdOrAnchorNameFragments,
 } = require("../src/utils.js")
 
 test("utils", async (t) => {
@@ -36,18 +36,22 @@ test("utils", async (t) => {
     )
   })
 
-  await t.test("getMarkdownAnchorHTMLFragments", async () => {
+  await t.test("getMarkdownIdOrAnchorNameFragments", async () => {
     assert.deepStrictEqual(
-      getMarkdownAnchorHTMLFragments(
+      getMarkdownIdOrAnchorNameFragments(
         '<a name="anchorName" id="anchorId">Link</a>',
       ),
       ["#anchorId"],
     )
     assert.deepStrictEqual(
-      getMarkdownAnchorHTMLFragments('<a name="anchorName">Link</a>'),
+      getMarkdownIdOrAnchorNameFragments('<a name="anchorName">Link</a>'),
       ["#anchorName"],
     )
-    assert.deepStrictEqual(getMarkdownAnchorHTMLFragments("<a>Link</a>"), [])
-    assert.deepStrictEqual(getMarkdownAnchorHTMLFragments("<a>"), [])
+    assert.deepStrictEqual(
+      getMarkdownIdOrAnchorNameFragments("<a>Link</a>"),
+      [],
+    )
+    assert.deepStrictEqual(getMarkdownIdOrAnchorNameFragments("<a>"), [])
+    assert.deepStrictEqual(getMarkdownIdOrAnchorNameFragments("<a id=>"), [])
   })
 })