FIX: Fix race condition when resolving tag and category hashtags (#10153)

* FIX: Fix race condition when resolving tag and category hashtags

If the category hashtags were resolved first and then tag hashtags, then
the tags would overwrite the categories. Similarly, if the category
hashtags were resolved last it would overwrite even hashtags which ended
with '::tag'.

* DEV: Add test

* DEV: Fix test

app/assets/javascripts/discourse/app/lib/category-hashtags.js

@@ -5,9 +5,10 @@ import {
   inCodeBlock
 } from "discourse/lib/utilities";
 
-export function replaceSpan($elem, categorySlug, categoryLink) {
+export function replaceSpan($elem, categorySlug, categoryLink, type) {
+  type = type ? ` data-type="${type}"` : "";
   $elem.replaceWith(
-    `<a href="${categoryLink}" class="hashtag">#<span>${categorySlug}</span></a>`
+    `<a href="${categoryLink}" class="hashtag"${type}>#<span>${categorySlug}</span></a>`
   );
 }
 

app/assets/javascripts/discourse/app/lib/link-category-hashtags.js

@@ -4,8 +4,7 @@ import { replaceSpan } from "discourse/lib/category-hashtags";
 
 const validCategoryHashtags = {};
 const checkedCategoryHashtags = [];
-const testedKey = "tested";
-const testedClass = `hashtag-${testedKey}`;
+const testedClass = `hashtag-category-tested`;
 
 function updateFound($hashtags, categorySlugs) {
   schedule("afterRender", () => {
@@ -15,16 +14,20 @@ function updateFound($hashtags, categorySlugs) {
       const $hashtag = $(hashtag);
 
       if (link) {
-        replaceSpan($hashtag, categorySlug, link);
+        if ($hashtag.data("type") !== "tag") {
+          replaceSpan($hashtag, categorySlug, link, "category");
+        }
       } else if (checkedCategoryHashtags.indexOf(categorySlug) !== -1) {
+        if (hashtag.tagName !== "A") {
           $hashtag.addClass(testedClass);
         }
+      }
     });
   });
 }
 
 export function linkSeenCategoryHashtags($elem) {
-  const $hashtags = $(`span.hashtag:not(.${testedClass})`, $elem);
+  const $hashtags = $(`span.hashtag:not(.${testedClass}), a.hashtag`, $elem);
   const unseen = [];
 
   if ($hashtags.length) {

app/assets/javascripts/discourse/app/lib/link-tag-hashtag.js

@@ -5,7 +5,7 @@ import { TAG_HASHTAG_POSTFIX } from "discourse/lib/tag-hashtags";
 
 const validTagHashtags = {};
 const checkedTagHashtags = [];
-const testedClass = "tag-hashtag-tested";
+const testedClass = "hashtag-tag-tested";
 
 function updateFound($hashtags, tagValues) {
   schedule("afterRender", () => {
@@ -15,7 +15,9 @@ function updateFound($hashtags, tagValues) {
       const $hashtag = $(hashtag);
 
       if (link) {
-        replaceSpan($hashtag, tagValue, link);
+        if (!$hashtag.data("type") || $hashtag.data("type") === "tag") {
+          replaceSpan($hashtag, tagValue, link, $hashtag.data("type"));
+        }
       } else if (checkedTagHashtags.indexOf(tagValue) !== -1) {
         $hashtag.addClass(testedClass);
       }
@@ -29,10 +31,12 @@ export function linkSeenTagHashtags($elem) {
 
   if ($hashtags.length) {
     const tagValues = $hashtags.map((_, hashtag) => {
-      return $(hashtag)
-        .text()
-        .substr(1)
-        .replace(TAG_HASHTAG_POSTFIX, "");
+      let text = $(hashtag).text();
+      if (text.endsWith(TAG_HASHTAG_POSTFIX)) {
+        text = text.slice(0, -TAG_HASHTAG_POSTFIX.length);
+        $(hashtag).data("type", "tag");
+      }
+      return text.substr(1);
     });
 
     if (tagValues.length) {

test/javascripts/acceptance/category-hashtag-test.js

@@ -13,6 +13,6 @@ QUnit.test("category hashtag is cooked properly", async assert => {
     find(".d-editor-preview:visible")
       .html()
       .trim(),
-    '<p>this is a category hashtag <a href="/c/bugs" class="hashtag">#<span>bug</span></a></p>'
+    '<p>this is a category hashtag <a href="/c/bugs" class="hashtag" data-type="category">#<span>bug</span></a></p>'
   );
 });

test/javascripts/acceptance/tag-hashtag-test.js

@@ -6,7 +6,10 @@ acceptance("Tag Hashtag", {
   pretend(server, helper) {
     server.get("/tags/check", () => {
       return helper.response({
-        valid: [{ value: "monkey", url: "/tag/monkey" }]
+        valid: [
+          { value: "monkey", url: "/tag/monkey" },
+          { value: "bug", url: "/tag/bug" }
+        ]
       });
     });
   }
@@ -16,8 +19,7 @@ QUnit.test("tag is cooked properly", async assert => {
   await visit("/t/internationalization-localization/280");
   await click("#topic-footer-buttons .btn.create");
 
-  await fillIn(".d-editor-input", "this is a tag hashtag #monkey::tag");
-  // TODO: Test that the autocomplete shows
+  await fillIn(".d-editor-input", "this is a tag hashtag #monkey");
   assert.equal(
     find(".d-editor-preview:visible")
       .html()
@@ -25,3 +27,19 @@ QUnit.test("tag is cooked properly", async assert => {
     '<p>this is a tag hashtag <a href="/tag/monkey" class="hashtag">#<span>monkey</span></a></p>'
   );
 });
+
+QUnit.test(
+  "tags and categories with same name are cooked properly",
+  async assert => {
+    await visit("/t/internationalization-localization/280");
+    await click("#topic-footer-buttons .btn.create");
+
+    await fillIn(".d-editor-input", "#bug vs #bug::tag");
+    assert.equal(
+      find(".d-editor-preview:visible")
+        .html()
+        .trim(),
+      '<p><a href="/c/bugs" class="hashtag" data-type="category">#<span>bug</span></a> vs <a href="/tag/bug" class="hashtag" data-type="tag">#<span>bug</span></a></p>'
+    );
+  }
+);