Merge pull request #4543 from EdgeApp/jon/fix/experiment-config-init

Jon/fix/experiment-config-init

Author: Jon-edge

CHANGELOG.md

@@ -9,6 +9,8 @@
 - changed: Change FlipInput styling to make the edit functionality more obvious
 - changed: Enable max spend for Filecoin
 - changed: Move asset-specific settings into their own settings page
+- changed: Experiment config probability distribution support percentage based values
+- fixed: Write updated experiment configs to disk
 - removed: Moonpay sell via ACH
 - removed: Banxa buy via Pix
 

src/experimentConfig.ts

@@ -26,34 +26,45 @@ const DEFAULT_EXPERIMENT_CONFIG: ExperimentConfig = {
 
 const experimentConfigDisklet = makeReactNativeDisklet()
 
-// The probability (0-1) of a feature config being set to the first value(s):
-// the configuration that differs from the default feature configuration.
+// The probability of an experiment config feature being set for a given key
 const experimentDistribution = {
-  swipeLastUsp: [0.5],
-  createAccountType: [0.5],
-  legacyLanding: [0],
-  createAccountText: [0.33, 0.33],
-  signupCaptcha: [0.5]
+  swipeLastUsp: [50, 50],
+  createAccountType: [50, 50],
+  legacyLanding: [100],
+  createAccountText: [33.33, 33.33, 33.33],
+  signupCaptcha: [50, 50]
 }
 
 /**
  * Generate a random index value according to the experiment distribution to
  * determine which variant gets used.
  */
 const generateExperimentConfigVal = <T>(key: keyof typeof experimentDistribution, configVals: T[]): T => {
-  const variantProbability = experimentDistribution[key]
+  const variantNominations = experimentDistribution[key]
 
-  if (variantProbability.length !== configVals.length - 1) {
+  if (variantNominations.length !== configVals.length) {
     console.error(`Misconfigured experimentDistribution for: '${key}'`)
   } else {
+    // Distribute the probability of each config value
+    const variantDenomination = variantNominations.reduce((sum, probability) => sum + probability, 0)
+    if (variantDenomination === 0) {
+      throw new Error(`Config values for '${key}' do not add up to 100%`)
+    } else if (variantDenomination > 101 || variantDenomination < 99) {
+      console.warn(`Config values for '${key}' do not add up to 100% +/- 1%`)
+    }
+    const distributedProbabilities = variantNominations.map(variantNomination => variantNomination / variantDenomination)
+
     // Generate a random number between 0 and 1
     const random = Math.random()
 
     // Check which index the random number falls into and return the configVal:
     let lowerBound = 0
-    for (let i = 0; i < variantProbability.length; i++) {
-      if (random >= lowerBound && random < variantProbability[i]) return configVals[i]
-      lowerBound += variantProbability[i]
+    let upperBound = distributedProbabilities[0]
+    for (let i = 0; i < distributedProbabilities.length; i++) {
+      if (random >= lowerBound && random < upperBound) return configVals[i]
+
+      lowerBound = upperBound
+      upperBound += distributedProbabilities[i]
     }
   }
 
@@ -81,17 +92,19 @@ const asExperimentConfig: Cleaner<ExperimentConfig> = asObject({
  * This config value is available through the module's getter functions.
  */
 const experimentConfigPromise: Promise<ExperimentConfig> = (async (): Promise<ExperimentConfig> => {
+  let currentConfig: ExperimentConfig
   try {
     const experimentConfigJson = await experimentConfigDisklet.getText(LOCAL_EXPERIMENT_CONFIG)
-    return asExperimentConfig(JSON.parse(experimentConfigJson))
+    currentConfig = asExperimentConfig(JSON.parse(experimentConfigJson))
   } catch (err) {
-    console.debug('Experiment config not found/out of date. Regenerating...')
+    console.log('Experiment config not found/out of date. Regenerating...')
     // Not found or incompatible. Re-generate with random values according to
     // the defined distribution.
-    const generatedExperimentConfig = asExperimentConfig({})
-    await experimentConfigDisklet.setText(LOCAL_EXPERIMENT_CONFIG, JSON.stringify(generatedExperimentConfig))
-    return generatedExperimentConfig
+    currentConfig = asExperimentConfig({})
   }
+
+  await experimentConfigDisklet.setText(LOCAL_EXPERIMENT_CONFIG, JSON.stringify(currentConfig))
+  return currentConfig
 })()
 
 /**
@@ -106,7 +119,7 @@ export const getExperimentConfig = async (): Promise<ExperimentConfig> => {
   if (isMaestro()) return DEFAULT_EXPERIMENT_CONFIG // Test with forced defaults
   else if (ENV.EXPERIMENT_CONFIG_OVERRIDE != null && Object.keys(ENV.EXPERIMENT_CONFIG_OVERRIDE).length > 0) {
     try {
-      console.debug('exp cfg override')
+      console.log('ENV.EXPERIMENT_CONFIG_OVERRIDE set')
       return asExperimentConfig(ENV.EXPERIMENT_CONFIG_OVERRIDE)
     } catch (err) {
       console.error('Error applying ENV.EXPERIMENT_CONFIG_OVERRIDE: ', String(err))