Drop TypeScript 3.8 support #18477

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#18604
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Drop TypeScript 3.8 support#18477
#18604
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logaretm
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State: BlockedTaskjavascriptPull requests that update javascript code

Description

@logaretm
logaretm
opened on Dec 11, 2025

Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

Reasons for dropping support:

  • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
  • Downlevel (tool we use for type conversion) is not maintained and outdated.
  • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.

Reasons against:

  • Users might still be using TS 3.8 types.


Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.

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    , 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
     blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

    Skip to content
    Drop TypeScript 3.8 support #18477
    Closed
    #18604
    Closed
    Drop TypeScript 3.8 support#18477
    #18604
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    logaretm
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    State: BlockedTaskjavascriptPull requests that update javascript code
    Description
    @logaretm
    logaretm
    opened on Dec 11, 2025
    Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

    Reasons for dropping support:
    • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
    • Downlevel (tool we use for type conversion) is not maintained and outdated.
    • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
    Reasons against:
    • Users might still be using TS 3.8 types.

    Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

    If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
    Activity
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    State: BlockedTaskjavascriptPull requests that update javascript code
    Projects
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      No milestone
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      None yet
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      No branches or pull requests
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

      Skip to content
      Drop TypeScript 3.8 support #18477
      Closed
      #18604
      Closed
      Drop TypeScript 3.8 support#18477
      #18604
      Assignees
      logaretm
      Labels
      State: BlockedTaskjavascriptPull requests that update javascript code
      Description
      @logaretm
      logaretm
      opened on Dec 11, 2025
      Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

      Reasons for dropping support:
      • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
      • Downlevel (tool we use for type conversion) is not maintained and outdated.
      • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
      Reasons against:
      • Users might still be using TS 3.8 types.

      Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

      If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
      Activity
      Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
      Metadata
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      Labels
      State: BlockedTaskjavascriptPull requests that update javascript code
      Projects
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        Milestone
        No milestone
        Relationships
        None yet
        Development
        No branches or pull requests
        Issue actions
        
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

        Skip to content
        Drop TypeScript 3.8 support #18477
        Closed
        #18604
        Closed
        Drop TypeScript 3.8 support#18477
        #18604
        Assignees
        logaretm
        Labels
        State: BlockedTaskjavascriptPull requests that update javascript code
        Description
        @logaretm
        logaretm
        opened on Dec 11, 2025
        Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

        Reasons for dropping support:
        • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
        • Downlevel (tool we use for type conversion) is not maintained and outdated.
        • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
        Reasons against:
        • Users might still be using TS 3.8 types.

        Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

        If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
        Activity
        Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
        Metadata
        Metadata
        Assignees
        Labels
        State: BlockedTaskjavascriptPull requests that update javascript code
        Projects
        No projects
          Milestone
          No milestone
          Relationships
          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

          Skip to content
          Drop TypeScript 3.8 support #18477
          Closed
          #18604
          Closed
          Drop TypeScript 3.8 support#18477
          #18604
          Assignees
          logaretm
          Labels
          State: BlockedTaskjavascriptPull requests that update javascript code
          Description
          @logaretm
          logaretm
          opened on Dec 11, 2025
          Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

          Reasons for dropping support:
          • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
          • Downlevel (tool we use for type conversion) is not maintained and outdated.
          • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
          Reasons against:
          • Users might still be using TS 3.8 types.

          Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

          If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
          Activity
          Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
          Metadata
          Metadata
          Assignees
          Labels
          State: BlockedTaskjavascriptPull requests that update javascript code
          Projects
          No projects
            Milestone
            No milestone
            Relationships
            None yet
            Development
            No branches or pull requests
            Issue actions
            
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

            Skip to content
            Drop TypeScript 3.8 support #18477
            Closed
            #18604
            Closed
            Drop TypeScript 3.8 support#18477
            #18604
            Assignees
            logaretm
            Labels
            State: BlockedTaskjavascriptPull requests that update javascript code
            Description
            @logaretm
            logaretm
            opened on Dec 11, 2025
            Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

            Reasons for dropping support:
            • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
            • Downlevel (tool we use for type conversion) is not maintained and outdated.
            • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
            Reasons against:
            • Users might still be using TS 3.8 types.

            Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

            If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
            Activity
            Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
            Metadata
            Metadata
            Assignees
            Labels
            State: BlockedTaskjavascriptPull requests that update javascript code
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              Drop TypeScript 3.8 support #18477
              Closed
              #18604
              Closed
              Drop TypeScript 3.8 support#18477
              #18604
              Assignees
              logaretm
              Labels
              State: BlockedTaskjavascriptPull requests that update javascript code
              Description
              @logaretm
              logaretm
              opened on Dec 11, 2025
              Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

              Reasons for dropping support:
              • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
              • Downlevel (tool we use for type conversion) is not maintained and outdated.
              • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
              Reasons against:
              • Users might still be using TS 3.8 types.

              Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

              If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
              Activity
              Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
              Metadata
              Metadata
              Assignees
              Labels
              State: BlockedTaskjavascriptPull requests that update javascript code
              Projects
              No projects
                Milestone
                No milestone
                Relationships
                None yet
                Development
                No branches or pull requests
                Issue actions
                
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

                Skip to content
                Drop TypeScript 3.8 support #18477
                Closed
                #18604
                Closed
                Drop TypeScript 3.8 support#18477
                #18604
                Assignees
                logaretm
                Labels
                State: BlockedTaskjavascriptPull requests that update javascript code
                Description
                @logaretm
                logaretm
                opened on Dec 11, 2025
                Following our discussion in Bikeshedding, we discussed the possibility of dropping downlevel process along with our support for TypeScript 3.8 types.

                Reasons for dropping support:
                • TypeScript 4 was released back in 2020, TypeScript 5 back in 2023.
                • Downlevel (tool we use for type conversion) is not maintained and outdated.
                • Downleveling limits the benefits of adopting rolldown as it creates a sync dependency between type generation and the bundling step.
                Reasons against:
                • Users might still be using TS 3.8 types.

                Our discussion resulted in deciding to tentatively drop support but also settle on the minimum TS supported version.

                If users complain about this we could re-introduce it as a release-only script rather than a core process of the build process.
                Activity
                Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
                Metadata
                Metadata
                Assignees
                Labels
                State: BlockedTaskjavascriptPull requests that update javascript code
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions