diff --git a/.github/workflows/test_typescript.yml b/.github/workflows/test_typescript.yml
new file mode 100644
index 000000000..bd4dac5c6
--- /dev/null
+++ b/.github/workflows/test_typescript.yml
@@ -0,0 +1,40 @@
+name: Runs with TypeScript Tests
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+
+      - name: Run TypeScript Compiler Tests with new dom.d.ts 
+        run: |
+          # Get local dependencies
+          npm install
+          # Make our new dom APIs
+          npm run build
+
+          # Clone TypeScript, set it up
+          git clone https://github.com/microsoft/TypeScript --depth 1
+
+          # Migrate the generated files into the repo
+          npm run migrate
+
+          cd TypeScript
+          npm i
+          
+
+          # Run TypeScript's tests with the new DOM libs, but don't fail
+          npm test || true
+          gulp baseline-accept
+
+          # The git diff now is the difference between tests 
+          git diff > baseline-changes.diff
+
+      - name: Danger
+        run: npm run danger -- ci
+        env: 
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
diff --git a/.gitignore b/.gitignore
index 9b2dda73d..72bc839d1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -285,3 +285,4 @@ inputfiles/browser.webidl.json
 !.vscode/launch.template.json
 package-lock.json
 yarn.lock
+TypeScript
diff --git a/dangerfile.js b/dangerfile.js
new file mode 100644
index 000000000..59101410f
--- /dev/null
+++ b/dangerfile.js
@@ -0,0 +1,34 @@
+const {markdown} = require("danger")
+const {readFileSync, existsSync} = require("fs")
+const parseDiff = require("parse-diff")
+
+const diffPath = "./TypeScript/baseline-changes.diff"
+if (existsSync(diffPath)) {
+  const diffContents = readFileSync(diffPath, "utf8")
+  const diffedFiles = parseDiff(diffContents)
+  
+  const uninterestingFiles = [".generated.d.ts", "globalThisBlockscopedProperties.types", "mappedTypeRecursiveInference.types"]
+  const withoutKnownNormalFails = diffedFiles.filter(diff => {
+    return !uninterestingFiles.filter(suffix => diff.to && diff.to.endsWith(suffix)).length > 0
+  })
+
+  const md = ["## Changed baselines from the TypeScript test suite", "\nThese are the test changes in the TypeScript codebase which showed a difference (excluding a few which will always change), it should give a small sense of what to expect on the TypeScript side if this PR is merged."]
+
+  withoutKnownNormalFails.forEach(diff => {
+    md.push(`#### [${diff.to || diff.from}](https://github.com/microsoft/TypeScript/blob/master/${diff.to || diff.from})`)
+    
+    md.push("```diff")
+    diff.chunks.forEach(chunk => {
+      md.push(chunk.content)
+
+      chunk.changes.forEach(change => {
+        md.push(change.content)
+      })
+    })
+    md.push("```")
+  })
+
+  if (md.length > 2) {
+    markdown(md.join("\n"))
+  }
+}
diff --git a/package.json b/package.json
index 1a309116d..1ffaf3304 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,7 @@
     "fetch": "echo This could take a few minutes... && npm run fetch-idl && npm run fetch-mdn",
     "baseline-accept": "cpx \"generated\\*\" baselines\\",
     "test": "tsc -p ./tsconfig.json && node ./lib/index.js && node ./lib/test.js",
+    "danger": "danger",
     "migrate": "node ./lib/migrate-to-tsc.js"
   },
   "dependencies": {
@@ -16,8 +17,10 @@
     "@types/node-fetch": "^2.5.7",
     "@types/webidl2": "^23.13.2",
     "cpx2": "^2.0.0",
+    "danger": "^10.5.4",
     "jsdom": "^16.4.0",
     "node-fetch": "^2.6.1",
+    "parse-diff": "^0.7.0",
     "print-diff": "^1.0.0",
     "styleless-innertext": "^1.1.2",
     "typescript": "4.1.0-dev.20200908",