diff --git a/packages/string-templates/manifest.json b/packages/string-templates/manifest.json
index ee03d75aa3..9dd8260350 100644
--- a/packages/string-templates/manifest.json
+++ b/packages/string-templates/manifest.json
@@ -1196,7 +1196,7 @@
         "durationType"
       ],
       "numArgs": 2,
-      "example": "{{duration timeLeft \"seconds\"}} -> a few seconds",
+      "example": "{{duration 8 \"seconds\"}} -> a few seconds",
       "description": "<p>Produce a humanized duration left/until given an amount of time and the type of time measurement.</p>\n"
     }
   }
diff --git a/packages/string-templates/scripts/gen-collection-info.js b/packages/string-templates/scripts/gen-collection-info.js
index 815f3b607f..b487c4dde4 100644
--- a/packages/string-templates/scripts/gen-collection-info.js
+++ b/packages/string-templates/scripts/gen-collection-info.js
@@ -36,7 +36,7 @@ const ADDED_HELPERS = {
     duration: {
       args: ["time", "durationType"],
       numArgs: 2,
-      example: '{{duration timeLeft "seconds"}} -> a few seconds',
+      example: '{{duration 8 "seconds"}} -> a few seconds',
       description:
         "Produce a humanized duration left/until given an amount of time and the type of time measurement.",
     },
diff --git a/packages/string-templates/test/manifest.spec.js b/packages/string-templates/test/manifest.spec.js
new file mode 100644
index 0000000000..506f2eb6f7
--- /dev/null
+++ b/packages/string-templates/test/manifest.spec.js
@@ -0,0 +1,96 @@
+jest.mock("@budibase/handlebars-helpers/lib/math", () => {
+  const actual = jest.requireActual("@budibase/handlebars-helpers/lib/math")
+
+  return {
+    ...actual,
+    random: () => 10,
+  }
+})
+jest.mock("@budibase/handlebars-helpers/lib/uuid", () => {
+  const actual = jest.requireActual("@budibase/handlebars-helpers/lib/uuid")
+
+  return {
+    ...actual,
+    uuid: () => "f34ebc66-93bd-4f7c-b79b-92b5569138bc",
+  }
+})
+
+const fs = require("fs")
+const { processString } = require("../src/index.cjs")
+
+const tk = require("timekeeper")
+tk.freeze("2021-01-21T12:00:00")
+
+const manifest = JSON.parse(
+  fs.readFileSync(require.resolve("../manifest.json"), "utf8")
+)
+
+const collections = Object.keys(manifest)
+const examples = collections.reduce((acc, collection) => {
+  const functions = Object.keys(manifest[collection]).filter(
+    fnc => manifest[collection][fnc].example
+  )
+  if (functions.length) {
+    acc[collection] = functions
+  }
+  return acc
+}, {})
+
+function escapeRegExp(string) {
+  return string.replace(/[.*+?^${}()|[\]\\]/g, "\\$&") // $& means the whole matched string
+}
+
+function tryParseJson(str) {
+  if (typeof str !== "string") {
+    return
+  }
+
+  try {
+    return JSON.parse(str.replace(/\'/g, '"'))
+  } catch (e) {
+    return
+  }
+}
+
+describe("manifest", () => {
+  describe("examples are valid", () => {
+    describe.each(Object.keys(examples))("%s", collection => {
+      it.each(examples[collection])("%s", async func => {
+        const example = manifest[collection][func].example
+
+        let [hbs, js] = example.split("->").map(x => x.trim())
+
+        const context = {
+          double: i => i * 2,
+          isString: x => typeof x === "string",
+        }
+
+        const arrays = hbs.match(/\[[^/\]]+\]/)
+        arrays?.forEach((arrayString, i) => {
+          hbs = hbs.replace(new RegExp(escapeRegExp(arrayString)), `array${i}`)
+          context[`array${i}`] = JSON.parse(arrayString.replace(/\'/g, '"'))
+        })
+
+        if (js === undefined) {
+          // The function has no return value
+          return
+        }
+
+        let result = await processString(hbs, context)
+        // Trim 's
+        js = js.replace(/^\'|\'$/g, "")
+        if ((parsedExpected = tryParseJson(js))) {
+          if (Array.isArray(parsedExpected)) {
+            if (typeof parsedExpected[0] === "object") {
+              js = JSON.stringify(parsedExpected)
+            } else {
+              js = parsedExpected.join(",")
+            }
+          }
+        }
+        result = result.replace(/&nbsp;/g, " ")
+        expect(result).toEqual(js)
+      })
+    })
+  })
+})
diff --git a/scripts/build-single-image.sh b/scripts/build-single-image.sh
index ba64d6121b..16b668e033 100755
--- a/scripts/build-single-image.sh
+++ b/scripts/build-single-image.sh
@@ -1,4 +1,4 @@
 #!/bin/bash
 yarn build --scope @budibase/server --scope @budibase/worker
 version=$(./scripts/getCurrentVersion.sh)
-docker build -f hosting/single/Dockerfile -t budibase:latest --build-arg BUDIBASE_VERSION=$version .
+docker build -f hosting/single/Dockerfile -t budibase:latest --build-arg BUDIBASE_VERSION=$version --build-arg TARGETBUILD=single .