feature(gatsby): Enable partial releases of flags to a % of users

examples/using-drupal/gatsby-config.js

@@ -1,7 +1,4 @@
 module.exports = {
-  flags: {
-    DEV_SSR: true,
-  },
   siteMetadata: {
     title: `Gatsby with Drupal`,
   },

packages/gatsby/src/services/initialize.ts

@@ -175,24 +175,25 @@ export async function initialize({
   }
 
   // Setup flags
-  if (config && config.flags) {
+  if (config) {
     // TODO: this should be handled in FAST_REFRESH configuration and not be one-off here.
     if (
-      config.flags.FAST_REFRESH &&
+      config.flags?.FAST_REFRESH &&
       process.env.GATSBY_HOT_LOADER &&
       process.env.GATSBY_HOT_LOADER !== `fast-refresh`
     ) {
       delete config.flags.FAST_REFRESH
       reporter.warn(
         reporter.stripIndent(`
           Both FAST_REFRESH gatsby-config flag and GATSBY_HOT_LOADER environment variable is used with conflicting setting ("${process.env.GATSBY_HOT_LOADER}").
-          
+
           Will use react-hot-loader.
-          
+
           To use Fast Refresh either do not use GATSBY_HOT_LOADER environment variable or set it to "fast-refresh".
         `)
       )
     }
+
     const availableFlags = require(`../utils/flags`).default
     // Get flags
     const { enabledConfigFlags, unknownFlagMessage, message } = handleFlags(
@@ -220,7 +221,7 @@ export async function initialize({
     })
 
     // Track the usage of config.flags
-    if (enabledConfigFlags.length > 0) {
+    if (config.flags) {
       telemetry.trackFeatureIsUsed(`ConfigFlags`)
     }
   }

packages/gatsby/src/utils/__tests__/__snapshots__/handle-flags.ts.snap

@@ -1,19 +1,159 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`handle flags filters out flags marked false 1`] = `
+Object {
+  "enabledConfigFlags": Array [
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_EXPERIMENTAL_SOMETHING_COOL",
+      "experimental": false,
+      "name": "ALL_COMMANDS",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO_NEW_LODASH",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE_ONLY_NEW_LODASH",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+  ],
+  "message": "The following flags are active:
+- ALL_COMMANDS · (Umbrella Issue (test)) · test
+
+We're shipping new features! For final testing, we're rolling them out first to a small % of Gatsby users
+and your site was automatically choosen as one of them. With your help, we'll then release them to everyone in the next minor release.
+
+We greatly appreciate your help testing the change. Please report any feedback good or bad in the umbrella issue. If you do encounter problems, please disable the flag by setting it to false in your gatsby-config.js like:
+
+flags: {
+  THE_FLAG: false
+}
+
+The following flags were automatically enabled on your site:
+- PARTIAL_RELEASE · (Umbrella Issue (test)) · test
+- PARTIAL_RELEASE_ONLY_NEW_LODASH · (Umbrella Issue (test)) · test
+
+There are 5 other flags available that you might be interested in:
+- FAST_DEV · Enable all experiments aimed at improving develop server start time
+- DEV_SSR · (Umbrella Issue (https://github.com/gatsbyjs/gatsby/discussions/28138)) · SSR pages on full reloads during develop. Helps you detect SSR bugs and fix them without needing to do full builds.
+- QUERY_ON_DEMAND · (Umbrella Issue (https://github.com/gatsbyjs/gatsby/discussions/27620)) · Only run queries when needed instead of running all queries upfront. Speeds starting the develop server.
+- ONLY_BUILDS · (Umbrella Issue (test)) · test
+- YET_ANOTHER · (Umbrella Issue (test)) · test
+",
+  "unknownFlagMessage": "",
+}
+`;
+
+exports[`handle flags opts in sites to a flag if their site is selected for partial release 1`] = `
+Object {
+  "enabledConfigFlags": Array [
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO_NEW_LODASH",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE_ONLY_NEW_LODASH",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+  ],
+  "message": "
+
+We're shipping new features! For final testing, we're rolling them out first to a small % of Gatsby users
+and your site was automatically choosen as one of them. With your help, we'll then release them to everyone in the next minor release.
+
+We greatly appreciate your help testing the change. Please report any feedback good or bad in the umbrella issue. If you do encounter problems, please disable the flag by setting it to false in your gatsby-config.js like:
+
+flags: {
+  THE_FLAG: false
+}
+
+The following flags were automatically enabled on your site:
+- PARTIAL_RELEASE · (Umbrella Issue (test)) · test
+- PARTIAL_RELEASE_ONLY_NEW_LODASH · (Umbrella Issue (test)) · test
+",
+  "unknownFlagMessage": "",
+}
+`;
+
 exports[`handle flags returns a message about unknown flags in the config 1`] = `
 Object {
   "enabledConfigFlags": Array [
     Object {
       "command": "all",
       "description": "test",
       "env": "GATSBY_EXPERIMENTAL_SOMETHING_COOL",
+      "experimental": false,
       "name": "ALL_COMMANDS",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO_NEW_LODASH",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE_ONLY_NEW_LODASH",
+      "telemetryId": "test",
+      "testFitness": [Function],
       "umbrellaIssue": "test",
     },
   ],
   "message": "The following flags are active:
 - ALL_COMMANDS · (Umbrella Issue (test)) · test
 
+We're shipping new features! For final testing, we're rolling them out first to a small % of Gatsby users
+and your site was automatically choosen as one of them. With your help, we'll then release them to everyone in the next minor release.
+
+We greatly appreciate your help testing the change. Please report any feedback good or bad in the umbrella issue. If you do encounter problems, please disable the flag by setting it to false in your gatsby-config.js like:
+
+flags: {
+  THE_FLAG: false
+}
+
+The following flags were automatically enabled on your site:
+- PARTIAL_RELEASE · (Umbrella Issue (test)) · test
+- PARTIAL_RELEASE_ONLY_NEW_LODASH · (Umbrella Issue (test)) · test
+
 There are 5 other flags available that you might be interested in:
 - FAST_DEV · Enable all experiments aimed at improving develop server start time
 - DEV_SSR · (Umbrella Issue (https://github.com/gatsbyjs/gatsby/discussions/28138)) · SSR pages on full reloads during develop. Helps you detect SSR bugs and fix them without needing to do full builds.
@@ -27,39 +167,71 @@ There are 5 other flags available that you might be interested in:
 }
 `;
 
-exports[`handle flags returns validConfigFlags and a message 1`] = `
+exports[`handle flags returns enabledConfigFlags and a message 1`] = `
 Object {
   "enabledConfigFlags": Array [
     Object {
       "command": "develop",
       "description": "Enable all experiments aimed at improving develop server start time",
       "env": "GATSBY_EXPERIMENTAL_FAST_DEV",
+      "experimental": false,
       "includedFlags": Array [
         "DEV_SSR",
         "QUERY_ON_DEMAND",
       ],
       "name": "FAST_DEV",
+      "telemetryId": "test",
+      "testFitness": [Function],
     },
     Object {
       "command": "all",
       "description": "test",
       "env": "GATSBY_EXPERIMENTAL_SOMETHING_COOL",
+      "experimental": false,
       "name": "ALL_COMMANDS",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE",
+      "telemetryId": "test",
+      "testFitness": [Function],
+      "umbrellaIssue": "test",
+    },
+    Object {
+      "command": "all",
+      "description": "test",
+      "env": "GATSBY_READY_TO_GO_NEW_LODASH",
+      "experimental": false,
+      "name": "PARTIAL_RELEASE_ONLY_NEW_LODASH",
+      "telemetryId": "test",
+      "testFitness": [Function],
       "umbrellaIssue": "test",
     },
     Object {
       "command": "develop",
       "description": "SSR pages on full reloads during develop. Helps you detect SSR bugs and fix them without needing to do full builds.",
       "env": "GATSBY_EXPERIMENTAL_DEV_SSR",
+      "experimental": false,
       "name": "DEV_SSR",
+      "telemetryId": "test",
+      "testFitness": [Function],
       "umbrellaIssue": "https://github.com/gatsbyjs/gatsby/discussions/28138",
     },
     Object {
       "command": "develop",
       "description": "Only run queries when needed instead of running all queries upfront. Speeds starting the develop server.",
       "env": "GATSBY_EXPERIMENTAL_QUERY_ON_DEMAND",
+      "experimental": false,
       "name": "QUERY_ON_DEMAND",
-      "noCi": true,
+      "noCI": true,
+      "telemetryId": "test",
+      "testFitness": [Function],
       "umbrellaIssue": "https://github.com/gatsbyjs/gatsby/discussions/27620",
     },
   ],
@@ -69,6 +241,19 @@ Object {
 - DEV_SSR · (Umbrella Issue (https://github.com/gatsbyjs/gatsby/discussions/28138)) · SSR pages on full reloads during develop. Helps you detect SSR bugs and fix them without needing to do full builds.
 - QUERY_ON_DEMAND · (Umbrella Issue (https://github.com/gatsbyjs/gatsby/discussions/27620)) · Only run queries when needed instead of running all queries upfront. Speeds starting the develop server.
 
+We're shipping new features! For final testing, we're rolling them out first to a small % of Gatsby users
+and your site was automatically choosen as one of them. With your help, we'll then release them to everyone in the next minor release.
+
+We greatly appreciate your help testing the change. Please report any feedback good or bad in the umbrella issue. If you do encounter problems, please disable the flag by setting it to false in your gatsby-config.js like:
+
+flags: {
+  THE_FLAG: false
+}
+
+The following flags were automatically enabled on your site:
+- PARTIAL_RELEASE · (Umbrella Issue (test)) · test
+- PARTIAL_RELEASE_ONLY_NEW_LODASH · (Umbrella Issue (test)) · test
+
 There are 2 other flags available that you might be interested in:
 - ONLY_BUILDS · (Umbrella Issue (test)) · test
 - YET_ANOTHER · (Umbrella Issue (test)) · test