diff --git a/package-lock.json b/package-lock.json
index 12fb4d00bd..219cf005f3 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -30,6 +30,16 @@
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       "dev": true
     },
+    "@sveltejs/svelte-repl": {
+      "version": "0.0.5",
+      "resolved": "https://registry.npmjs.org/@sveltejs/svelte-repl/-/svelte-repl-0.0.5.tgz",
+      "integrity": "sha512-SKSX4xkqwH0XcUHQozwTNm3OCqatk66CXYZnqOW9Jf4E1B6opyQUb9f96KwAxh7ghZMbeePRv51oOWsw6n0Yww==",
+      "dev": true,
+      "requires": {
+        "codemirror": "^5.45.0",
+        "yootils": "0.0.15"
+      }
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       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-0.0.39.tgz",
@@ -139,7 +149,7 @@
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       "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/ansi-escapes/-/ansi-escapes-3.1.0.tgz",
+      "resolved": "http://registry.npmjs.org/ansi-escapes/-/ansi-escapes-3.1.0.tgz",
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       "dev": true
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@@ -199,7 +209,7 @@
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     "array-equal": {
       "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/array-equal/-/array-equal-1.0.0.tgz",
+      "resolved": "http://registry.npmjs.org/array-equal/-/array-equal-1.0.0.tgz",
       "integrity": "sha1-jCpe8kcv2ep0KwTHenUJO6J1fJM=",
       "dev": true
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@@ -591,6 +601,12 @@
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+    "codemirror": {
+      "version": "5.45.0",
+      "resolved": "https://registry.npmjs.org/codemirror/-/codemirror-5.45.0.tgz",
+      "integrity": "sha512-c19j644usCE8gQaXa0jqn2B/HN9MnB2u6qPIrrhrMkB+QAP42y8G4QnTwuwbVSoUS1jEl7JU9HZMGhCDL0nsAw==",
+      "dev": true
+    },
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       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/collection-visit/-/collection-visit-1.0.0.tgz",
@@ -627,7 +643,7 @@
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-      "resolved": "https://registry.npmjs.org/commander/-/commander-2.15.1.tgz",
+      "resolved": "http://registry.npmjs.org/commander/-/commander-2.15.1.tgz",
       "integrity": "sha512-VlfT9F3V0v+jr4yxPc5gg9s62/fIVWsd2Bk2iD435um1NlGMYdVCq+MjcXnhYq2icNOizHr1kK+5TI6H0Hy0ag==",
       "dev": true
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@@ -878,7 +894,7 @@
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           "version": "1.1.3",
-          "resolved": "https://registry.npmjs.org/domelementtype/-/domelementtype-1.1.3.tgz",
+          "resolved": "http://registry.npmjs.org/domelementtype/-/domelementtype-1.1.3.tgz",
           "integrity": "sha1-vSh3PiZCiBrsUVRJJCmcXNgiGFs=",
           "dev": true
         }
@@ -1131,7 +1147,7 @@
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         "doctrine": {
           "version": "1.5.0",
-          "resolved": "https://registry.npmjs.org/doctrine/-/doctrine-1.5.0.tgz",
+          "resolved": "http://registry.npmjs.org/doctrine/-/doctrine-1.5.0.tgz",
           "integrity": "sha1-N53Ocw9hZvds76TmcHoVmwLFpvo=",
           "dev": true,
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@@ -1826,7 +1842,7 @@
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     "is-builtin-module": {
       "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/is-builtin-module/-/is-builtin-module-1.0.0.tgz",
+      "resolved": "http://registry.npmjs.org/is-builtin-module/-/is-builtin-module-1.0.0.tgz",
       "integrity": "sha1-VAVy0096wxGfj3bDDLwbHgN6/74=",
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@@ -2112,7 +2128,7 @@
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       "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/load-json-file/-/load-json-file-2.0.0.tgz",
+      "resolved": "http://registry.npmjs.org/load-json-file/-/load-json-file-2.0.0.tgz",
       "integrity": "sha1-eUfkIUmvgNaWy/eXvKq8/h/inKg=",
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@@ -2271,7 +2287,7 @@
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     "minimist": {
       "version": "0.0.8",
-      "resolved": "https://registry.npmjs.org/minimist/-/minimist-0.0.8.tgz",
+      "resolved": "http://registry.npmjs.org/minimist/-/minimist-0.0.8.tgz",
       "integrity": "sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0=",
       "dev": true
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@@ -2298,7 +2314,7 @@
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     "mkdirp": {
       "version": "0.5.1",
-      "resolved": "https://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz",
+      "resolved": "http://registry.npmjs.org/mkdirp/-/mkdirp-0.5.1.tgz",
       "integrity": "sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=",
       "dev": true,
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@@ -2608,7 +2624,7 @@
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       "version": "1.0.2",
-      "resolved": "https://registry.npmjs.org/os-tmpdir/-/os-tmpdir-1.0.2.tgz",
+      "resolved": "http://registry.npmjs.org/os-tmpdir/-/os-tmpdir-1.0.2.tgz",
       "integrity": "sha1-u+Z0BseaqFxc/sdm/lc0VV36EnQ=",
       "dev": true
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@@ -2692,7 +2708,7 @@
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     "path-is-absolute": {
       "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/path-is-absolute/-/path-is-absolute-1.0.1.tgz",
+      "resolved": "http://registry.npmjs.org/path-is-absolute/-/path-is-absolute-1.0.1.tgz",
       "integrity": "sha1-F0uSaHNVNP+8es5r9TpanhtcX18=",
       "dev": true
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@@ -2737,7 +2753,7 @@
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     "pify": {
       "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
+      "resolved": "http://registry.npmjs.org/pify/-/pify-2.3.0.tgz",
       "integrity": "sha1-7RQaasBDqEnqWISY59yosVMw6Qw=",
       "dev": true
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@@ -3440,7 +3456,7 @@
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     "safe-regex": {
       "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/safe-regex/-/safe-regex-1.1.0.tgz",
+      "resolved": "http://registry.npmjs.org/safe-regex/-/safe-regex-1.1.0.tgz",
       "integrity": "sha1-QKNmnzsHfR6UPURinhV91IAjvy4=",
       "dev": true,
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@@ -4024,7 +4040,7 @@
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     "through": {
       "version": "2.3.8",
-      "resolved": "https://registry.npmjs.org/through/-/through-2.3.8.tgz",
+      "resolved": "http://registry.npmjs.org/through/-/through-2.3.8.tgz",
       "integrity": "sha1-DdTJ/6q8NXlgsbckEV1+Doai4fU=",
       "dev": true
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@@ -4607,6 +4623,12 @@
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       "integrity": "sha512-+Wo/p5VRfxUgBUGy2j/6KX2mj9AYJWOHuhMjMcbBFc3y54o9/4buK1ksBvuiK01C3kby8DH9lSmJdSxw+4G/2Q==",
       "dev": true
+    },
+    "yootils": {
+      "version": "0.0.15",
+      "resolved": "https://registry.npmjs.org/yootils/-/yootils-0.0.15.tgz",
+      "integrity": "sha512-GvGLuJ7XHJPGEUQ52vh8fh+vPjfikuGcu7yBswfrsNsHqnAoytOVuSb69eM0j8wQIjMz0U3kY3YsfwMhJgfG9w==",
+      "dev": true
     }
   }
 }
diff --git a/package.json b/package.json
index f9aa16656d..df3538d847 100644
--- a/package.json
+++ b/package.json
@@ -49,6 +49,7 @@
   },
   "homepage": "https://github.com/sveltejs/svelte#README",
   "devDependencies": {
+    "@sveltejs/svelte-repl": "0.0.5",
     "@types/mocha": "^5.2.0",
     "@types/node": "^10.5.5",
     "acorn": "^6.1.1",