diff --git a/.circleci/config.yml b/.circleci/config.yml
index 87f6d0cc9c24f..f3d00641a0510 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -83,7 +83,7 @@ aliases:
             yarn why lmdb-store
       - run:
           name: Run tests
-          command: yarn jest --ci --runInBand $(yarn jest --listTests | sed 's/\/root\/project//g' | circleci tests split --split-by=timings)
+          command: yarn jest --ci --runInBand  $(yarn -s jest --listTests | sed 's/\/home\/circleci\/project\///g' | circleci tests split)
           environment:
             NODE_OPTIONS: --max-old-space-size=2048
             GENERATE_JEST_REPORT: true
diff --git a/packages/babel-preset-gatsby-package/lib/__tests__/__snapshots__/index.js.snap b/packages/babel-preset-gatsby-package/lib/__tests__/__snapshots__/index.js.snap
index fe740e23f89f9..9e149bc763efa 100644
--- a/packages/babel-preset-gatsby-package/lib/__tests__/__snapshots__/index.js.snap
+++ b/packages/babel-preset-gatsby-package/lib/__tests__/__snapshots__/index.js.snap
@@ -90,7 +90,9 @@ Array [
       "availableFlags": Array [
         "GATSBY_MAJOR",
       ],
-      "flags": Object {},
+      "flags": Object {
+        "GATSBY_MAJOR": "4",
+      },
     },
   ],
 ]
@@ -109,7 +111,9 @@ Array [
       "availableFlags": Array [
         "MAJOR",
       ],
-      "flags": Object {},
+      "flags": Object {
+        "GATSBY_MAJOR": "4",
+      },
     },
   ],
 ]
@@ -176,7 +180,9 @@ Array [
       "availableFlags": Array [
         "GATSBY_MAJOR",
       ],
-      "flags": Object {},
+      "flags": Object {
+        "GATSBY_MAJOR": "4",
+      },
     },
   ],
 ]
diff --git a/packages/babel-preset-gatsby-package/package.json b/packages/babel-preset-gatsby-package/package.json
index 36d0dc9975a2c..197bbbad4332b 100644
--- a/packages/babel-preset-gatsby-package/package.json
+++ b/packages/babel-preset-gatsby-package/package.json
@@ -26,7 +26,8 @@
     "@babel/core": "^7.15.5",
     "@babel/helper-plugin-test-runner": "7.14.5",
     "@babel/plugin-transform-modules-commonjs": "^7.15.4",
-    "@types/babel__core": "^7.1.15"
+    "@types/babel__core": "^7.1.15",
+    "cross-env": "^7.0.3"
   },
   "peerDependencies": {
     "@babel/core": "^7.11.6"
diff --git a/packages/gatsby-cli/src/index.ts b/packages/gatsby-cli/src/index.ts
index d69fa34dde30e..d6b4321b56d6a 100755
--- a/packages/gatsby-cli/src/index.ts
+++ b/packages/gatsby-cli/src/index.ts
@@ -23,7 +23,7 @@ if (os.platform() === `win32`) {
 // Check if update is available
 updateNotifier({ pkg }).notify({ isGlobal: true })
 
-const MIN_NODE_VERSION = `12.13.0`
+const MIN_NODE_VERSION = `14.15.0`
 // const NEXT_MIN_NODE_VERSION = `10.13.0`
 
 const { version } = process
diff --git a/packages/gatsby-plugin-mdx/__tests__/gatsby-node.js b/packages/gatsby-plugin-mdx/__tests__/gatsby-node.js
index 0c7bacc5ae648..df7deffbfa0ba 100644
--- a/packages/gatsby-plugin-mdx/__tests__/gatsby-node.js
+++ b/packages/gatsby-plugin-mdx/__tests__/gatsby-node.js
@@ -8,8 +8,8 @@ describe(`pluginOptionsSchema`, () => {
       `"extensions[1]" must be a string`,
       `"extensions[2]" must be a string`,
       `"defaultLayouts" must be of type object`,
-      `"gatsbyRemarkPlugins[0]" does not match any of the allowed types`,
-      `"gatsbyRemarkPlugins[1]" does not match any of the allowed types`,
+      `"gatsbyRemarkPlugins[0]" must be one of [string, object]`,
+      `"gatsbyRemarkPlugins[1].not" is not allowed`,
       `"remarkPlugins" must be an array`,
       `"rehypePlugins" must be an array`,
       `"plugins[0]" does not match any of the allowed types`,
diff --git a/packages/gatsby-plugin-mdx/utils/__tests__/gen-mdx.js b/packages/gatsby-plugin-mdx/utils/__tests__/gen-mdx.js
index fe7341f21eaa9..457dfcb1205e4 100644
--- a/packages/gatsby-plugin-mdx/utils/__tests__/gen-mdx.js
+++ b/packages/gatsby-plugin-mdx/utils/__tests__/gen-mdx.js
@@ -16,6 +16,7 @@ console.log('hello world')
 
 describe(`find imports`, () => {
   it(`allows injecting imports via plugins`, async () => {
+    const testPluginModulePath = path.join(__dirname, `fixtures`, `test-plugin`)
     const results = await findImports({
       node: {
         id: `bbffffbb-bfff-bfff-bfff-dededededede`,
@@ -37,7 +38,10 @@ describe(`find imports`, () => {
       options: {
         remarkPlugins: [],
         gatsbyRemarkPlugins: [
-          { resolve: path.join(__dirname, `fixtures`, `test-plugin`) },
+          {
+            resolve: testPluginModulePath,
+            module: require(testPluginModulePath),
+          },
         ],
       },
       getNode: () => null,
diff --git a/packages/gatsby-plugin-utils/src/test-plugin-options-schema.ts b/packages/gatsby-plugin-utils/src/test-plugin-options-schema.ts
index 81c949b5bc2f2..da006fcce75f0 100644
--- a/packages/gatsby-plugin-utils/src/test-plugin-options-schema.ts
+++ b/packages/gatsby-plugin-utils/src/test-plugin-options-schema.ts
@@ -12,7 +12,35 @@ export async function testPluginOptionsSchema(
   pluginSchemaFunction: Exclude<GatsbyNode["pluginOptionsSchema"], undefined>,
   pluginOptions: IPluginInfoOptions
 ): Promise<ITestPluginOptionsSchemaReturnType> {
-  const pluginSchema = pluginSchemaFunction({ Joi })
+  const pluginSchema = pluginSchemaFunction({
+    Joi: Joi.extend(joi => {
+      return {
+        base: joi.any(),
+        type: `subPlugins`,
+        args: (): any =>
+          joi
+            .array()
+            .items(
+              joi
+                .alternatives(
+                  joi.string(),
+                  joi.object({
+                    resolve: Joi.string(),
+                    options: Joi.object({}).unknown(true),
+                  })
+                )
+                .custom(value => {
+                  if (typeof value === `string`) {
+                    value = { resolve: value }
+                  }
+
+                  return value
+                }, `Gatsby specific subplugin validation`)
+            )
+            .default([]),
+      }
+    }),
+  })
 
   try {
     await validateOptionsSchema(pluginSchema, pluginOptions)
diff --git a/packages/gatsby-transformer-remark/src/__tests__/extend-node.js b/packages/gatsby-transformer-remark/src/__tests__/extend-node.js
index 6a6f004a3db89..dcdd02922add3 100644
--- a/packages/gatsby-transformer-remark/src/__tests__/extend-node.js
+++ b/packages/gatsby-transformer-remark/src/__tests__/extend-node.js
@@ -1143,6 +1143,7 @@ It's easier than you may imagine`,
               showLineNumbers: false,
               noInlineHighlight: false,
             },
+            module: require(`gatsby-remark-prismjs`),
           },
         ],
       },
@@ -1335,6 +1336,7 @@ describe(`Headings are generated correctly from schema`, () => {
           {
             resolve: require.resolve(`gatsby-remark-autolink-headers/src`),
             pluginOptions: {},
+            module: require(`gatsby-remark-autolink-headers/src`),
           },
         ],
       },
diff --git a/packages/gatsby/scripts/__tests__/api.js b/packages/gatsby/scripts/__tests__/api.js
index 593059e8ce43b..a1b6e3bd2bf6d 100644
--- a/packages/gatsby/scripts/__tests__/api.js
+++ b/packages/gatsby/scripts/__tests__/api.js
@@ -44,6 +44,9 @@ it("generates the expected api output", done => {
           "onCreateNode": Object {},
           "onCreatePage": Object {},
           "onCreateWebpackConfig": Object {},
+          "onPluginInit": Object {
+            "version": "3.9.0",
+          },
           "onPostBootstrap": Object {},
           "onPostBuild": Object {},
           "onPreBootstrap": Object {},
@@ -57,9 +60,6 @@ it("generates the expected api output", done => {
           "resolvableExtensions": Object {},
           "setFieldsOnGraphQLNodeType": Object {},
           "sourceNodes": Object {},
-          "onPluginInit": Object {
-            "version": "3.9.0",
-          },
           "unstable_shouldOnCreateNode": Object {
             "version": "2.24.80",
           },
diff --git a/packages/gatsby/src/bootstrap/__tests__/redirects-writer.ts b/packages/gatsby/src/bootstrap/__tests__/redirects-writer.ts
index b1db0ed179bde..ada1749be3398 100644
--- a/packages/gatsby/src/bootstrap/__tests__/redirects-writer.ts
+++ b/packages/gatsby/src/bootstrap/__tests__/redirects-writer.ts
@@ -5,7 +5,7 @@ import { store } from "../../redux"
 import { actions } from "../../redux/actions"
 
 jest.mock(`fs-extra`, () => {
-  return { writeFile: jest.fn() }
+  return { writeFile: jest.fn(), readFileSync: jest.fn(() => `foo`) }
 })
 
 jest.mock(`gatsby-cli/lib/reporter`, () => {
diff --git a/packages/gatsby/src/bootstrap/__tests__/requires-writer.js b/packages/gatsby/src/bootstrap/__tests__/requires-writer.js
index dd772a3fab652..945c8a53c818a 100644
--- a/packages/gatsby/src/bootstrap/__tests__/requires-writer.js
+++ b/packages/gatsby/src/bootstrap/__tests__/requires-writer.js
@@ -10,6 +10,7 @@ const generatePagesState = pages => {
     state.set(page.path, {
       component: ``,
       componentChunkName: ``,
+      mode: `SSG`,
       ...page,
     })
   })
diff --git a/packages/gatsby/src/bootstrap/load-plugins/__tests__/__snapshots__/load-plugins.ts.snap b/packages/gatsby/src/bootstrap/load-plugins/__tests__/__snapshots__/load-plugins.ts.snap
index 1140f0072e9b6..c28c6f35d04de 100644
--- a/packages/gatsby/src/bootstrap/load-plugins/__tests__/__snapshots__/load-plugins.ts.snap
+++ b/packages/gatsby/src/bootstrap/load-plugins/__tests__/__snapshots__/load-plugins.ts.snap
@@ -110,7 +110,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/dev-404-page/src/pages",
@@ -131,7 +131,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/load-babel-config/src/pages",
@@ -152,7 +152,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/internal-data-bridge/src/pages",
@@ -173,7 +173,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/prod-404/src/pages",
@@ -194,7 +194,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/webpack-theme-component-shadowing/src/pages",
@@ -215,7 +215,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/bundle-optimisations/src/pages",
@@ -236,7 +236,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/functions/src/pages",
@@ -292,7 +292,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "/src/pages",
@@ -429,7 +429,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/dev-404-page/src/pages",
@@ -450,7 +450,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/load-babel-config/src/pages",
@@ -471,7 +471,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/internal-data-bridge/src/pages",
@@ -492,7 +492,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/prod-404/src/pages",
@@ -513,7 +513,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/webpack-theme-component-shadowing/src/pages",
@@ -534,7 +534,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/bundle-optimisations/src/pages",
@@ -555,7 +555,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/functions/src/pages",
@@ -576,7 +576,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "__TEST__/src/pages",
@@ -632,7 +632,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "/src/pages",
@@ -757,7 +757,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "ignore": Array [
@@ -780,7 +780,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/dev-404-page/src/pages",
@@ -801,7 +801,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/load-babel-config/src/pages",
@@ -822,7 +822,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/internal-data-bridge/src/pages",
@@ -843,7 +843,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/prod-404/src/pages",
@@ -864,7 +864,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/webpack-theme-component-shadowing/src/pages",
@@ -885,7 +885,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/bundle-optimisations/src/pages",
@@ -906,7 +906,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby/src/internal-plugins/functions/src/pages",
@@ -927,7 +927,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "<PROJECT_ROOT>/packages/gatsby-plugin-page-creator/src/pages",
@@ -983,7 +983,7 @@ Array [
     "nodeAPIs": Array [
       "createPagesStatefully",
       "setFieldsOnGraphQLNodeType",
-      "unstable_onPluginInit",
+      "onPluginInit",
     ],
     "pluginOptions": Object {
       "path": "/src/pages",
diff --git a/packages/gatsby/src/commands/__tests__/build-utils.ts b/packages/gatsby/src/commands/__tests__/build-utils.ts
index 9fccdde11da4b..b5609acf8db58 100644
--- a/packages/gatsby/src/commands/__tests__/build-utils.ts
+++ b/packages/gatsby/src/commands/__tests__/build-utils.ts
@@ -56,6 +56,7 @@ describe(`calcDirtyHtmlFiles`, () => {
           // eslint-disable-next-line @typescript-eslint/naming-convention
           pluginCreator___NODE: `foo`,
           updatedAt: 1,
+          mode: `SSG`,
         })
       }
 
diff --git a/packages/gatsby/src/query/__tests__/data-tracking.js b/packages/gatsby/src/query/__tests__/data-tracking.js
index 92ad2cd01c100..ad5f58e8ab987 100644
--- a/packages/gatsby/src/query/__tests__/data-tracking.js
+++ b/packages/gatsby/src/query/__tests__/data-tracking.js
@@ -31,6 +31,7 @@ jest.mock(`fs-extra`, () => {
   return {
     outputFile: jest.fn(),
     ensureDir: jest.fn(),
+    readFileSync: jest.fn(() => `foo`), // createPage action reads the page template file trying to find `getServerData`
   }
 })
 
diff --git a/packages/gatsby/src/redux/__tests__/__snapshots__/index.js.snap b/packages/gatsby/src/redux/__tests__/__snapshots__/index.js.snap
index 5d1c5abb60fcb..586089419a3b0 100644
--- a/packages/gatsby/src/redux/__tests__/__snapshots__/index.js.snap
+++ b/packages/gatsby/src/redux/__tests__/__snapshots__/index.js.snap
@@ -74,6 +74,7 @@ Object {
       "internalComponentName": "Component/my-sweet-new-page/",
       "isCreatedByStatefulCreatePages": false,
       "matchPath": undefined,
+      "mode": "SSG",
       "path": "/my-sweet-new-page/",
       "pluginCreatorId": "",
       "pluginCreator___NODE": "",
diff --git a/packages/gatsby/src/redux/__tests__/__snapshots__/pages.ts.snap b/packages/gatsby/src/redux/__tests__/__snapshots__/pages.ts.snap
index 0f69a6cf7fb09..4e7b2140fdc3e 100644
--- a/packages/gatsby/src/redux/__tests__/__snapshots__/pages.ts.snap
+++ b/packages/gatsby/src/redux/__tests__/__snapshots__/pages.ts.snap
@@ -54,6 +54,7 @@ Map {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -66,6 +67,7 @@ Map {
     "internalComponentName": "Component/hi/pizza/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/pizza/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -84,6 +86,7 @@ Object {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -106,6 +109,7 @@ Map {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -126,6 +130,7 @@ Object {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -150,6 +155,7 @@ Map {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -168,6 +174,7 @@ Object {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": "/hi-from-somewhere-else/",
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -190,6 +197,7 @@ Map {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": "/hi-from-somewhere-else/",
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
@@ -209,6 +217,7 @@ Map {
     "internalComponentName": "Component/hi/",
     "isCreatedByStatefulCreatePages": false,
     "matchPath": undefined,
+    "mode": "SSG",
     "path": "/hi/",
     "pluginCreatorId": "test",
     "pluginCreator___NODE": "test",
diff --git a/packages/gatsby/src/redux/__tests__/index.js b/packages/gatsby/src/redux/__tests__/index.js
index 15deb515c44f1..ee58c77282a68 100644
--- a/packages/gatsby/src/redux/__tests__/index.js
+++ b/packages/gatsby/src/redux/__tests__/index.js
@@ -21,6 +21,7 @@ const {
   actions: { createPage, createNode },
 } = require(`../actions`)
 
+const pageTemplatePath = `/Users/username/dev/site/src/templates/my-sweet-new-page.js`
 const mockWrittenContent = new Map()
 const mockCompatiblePath = path
 jest.mock(`fs-extra`, () => {
@@ -131,7 +132,7 @@ describe(`redux db`, () => {
   const defaultPage = {
     path: `/my-sweet-new-page/`,
     // seems like jest serializer doesn't play nice with Maps on Windows
-    component: `/Users/username/dev/site/src/templates/my-sweet-new-page.js`,
+    component: pageTemplatePath,
     // The context is passed as props to the component as well
     // as into the component's GraphQL query.
     context: {
@@ -146,6 +147,7 @@ describe(`redux db`, () => {
     })
     writeToCache.mockClear()
     mockWrittenContent.clear()
+    mockWrittenContent.set(pageTemplatePath, `foo`)
     reporterWarn.mockClear()
     reporterInfo.mockClear()
   })
@@ -530,8 +532,16 @@ describe(`redux db`, () => {
     it(`saves with correct filename (with defaults)`, () => {
       savePartialStateToDisk([`pages`])
 
-      const savedFile = mockWrittenContent.keys().next().value
-      const basename = path.basename(savedFile)
+      let basename
+      // get first non page template mocked fs write
+      for (const savedFile of mockWrittenContent.keys()) {
+        if (savedFile === pageTemplatePath) {
+          continue
+        }
+
+        basename = path.basename(savedFile)
+        break
+      }
 
       expect(basename.startsWith(`redux.worker.slices__`)).toBe(true)
     })
@@ -549,8 +559,16 @@ describe(`redux db`, () => {
     it(`respects optionalPrefix`, () => {
       savePartialStateToDisk([`pages`], `custom-prefix`)
 
-      const savedFile = mockWrittenContent.keys().next().value
-      const basename = path.basename(savedFile)
+      let basename
+      // get first non page template mocked fs write
+      for (const savedFile of mockWrittenContent.keys()) {
+        if (savedFile === pageTemplatePath) {
+          continue
+        }
+
+        basename = path.basename(savedFile)
+        break
+      }
 
       expect(basename.startsWith(`redux.worker.slices_custom-prefix_`)).toBe(
         true
diff --git a/packages/gatsby/src/redux/__tests__/pages.ts b/packages/gatsby/src/redux/__tests__/pages.ts
index dd42d4c73cc76..60d5b7dd25db6 100644
--- a/packages/gatsby/src/redux/__tests__/pages.ts
+++ b/packages/gatsby/src/redux/__tests__/pages.ts
@@ -3,6 +3,7 @@ import { readFile } from "fs-extra"
 jest.mock(`fs-extra`, () => {
   return {
     readFile: jest.fn(() => `contents`),
+    readFileSync: jest.fn(() => `foo`), // createPage action reads the page template file trying to find `getServerData`
   }
 })
 import glob from "glob"
diff --git a/packages/gatsby/src/services/__tests__/create-pages.ts b/packages/gatsby/src/services/__tests__/create-pages.ts
index 20d8087a4e0eb..4ec43929473d0 100644
--- a/packages/gatsby/src/services/__tests__/create-pages.ts
+++ b/packages/gatsby/src/services/__tests__/create-pages.ts
@@ -10,6 +10,12 @@ jest.mock(`../../utils/js-chunk-names`, () => {
   return { generateComponentChunkName: (): string => `--mocked--` }
 })
 
+jest.mock(`fs-extra`, () => {
+  return {
+    readFileSync: jest.fn(() => `foo`), // createPage action reads the page template file trying to find `getServerData`
+  }
+})
+
 let mockAPIs = {}
 
 const component = path.join(process.cwd(), `wat`)
diff --git a/packages/gatsby/src/utils/__tests__/get-page-data.ts b/packages/gatsby/src/utils/__tests__/get-page-data.ts
index 796a037e54963..b32368866d4ea 100644
--- a/packages/gatsby/src/utils/__tests__/get-page-data.ts
+++ b/packages/gatsby/src/utils/__tests__/get-page-data.ts
@@ -95,6 +95,7 @@ describe(`get-page-data-util`, () => {
         path: `/foo`,
         componentPath: `/foo.js`,
         component: `/foo.js`,
+        mode: `SSG`, // TODO: need to test other modes in non-build environment
       },
     }