Add diff log to env:pull command

Author: khamilowicz

CHANGELOG.md

@@ -8,6 +8,8 @@ This is the log of notable changes to EAS CLI and related packages.
 
 ### 🎉 New features
 
+- Add diff to `eas env:pull` command. ([#2984](https://github.com/expo/eas-cli/pull/2984) by [@khamilowicz](https://github.com/khamilowicz))
+
 ### 🐛 Bug fixes
 
 ### 🧹 Chores

packages/eas-cli/src/commands/env/pull.ts

@@ -1,4 +1,5 @@
 import { Flags } from '@oclif/core';
+import chalk from 'chalk';
 import dotenv from 'dotenv';
 import * as fs from 'fs-extra';
 import path from 'path';
@@ -43,6 +44,31 @@ export default class EnvPull extends EasCommand {
     }),
   };
 
+  async isVariableEqualAsync(
+    currentEnvValue: string | undefined,
+    newVariable: EnvironmentVariableWithFileContent
+  ): Promise<boolean> {
+    if (newVariable.visibility === EnvironmentVariableVisibility.Secret) {
+      return true;
+    }
+
+    if (
+      newVariable.type === EnvironmentSecretType.FileBase64 &&
+      newVariable.valueWithFileContent &&
+      currentEnvValue
+    ) {
+      if (!(await fs.exists(currentEnvValue))) {
+        return false;
+      }
+
+      const fileContent = await fs.readFile(currentEnvValue, 'base64');
+
+      return fileContent === newVariable.valueWithFileContent;
+    }
+
+    return currentEnvValue === newVariable.value;
+  }
+
   async runAsync(): Promise<void> {
     let {
       args: { environment: argEnvironment },
@@ -105,6 +131,31 @@ export default class EnvPull extends EasCommand {
       await fs.mkdir(envDir, { recursive: true });
     }
 
+    const allVariableNames = new Set([
+      ...environmentVariables.map(v => v.name),
+      ...Object.keys(currentEnvLocal),
+    ]);
+
+    const diffLog = [];
+
+    for (const variableName of allVariableNames) {
+      const newVariable = environmentVariables.find(v => v.name === variableName);
+      if (newVariable) {
+        if (Object.hasOwn(currentEnvLocal, variableName)) {
+          if (await this.isVariableEqualAsync(currentEnvLocal[variableName], newVariable)) {
+            diffLog.push(chalk.black(`  ${variableName}`));
+          } else {
+            diffLog.push(chalk.yellow(`~ ${variableName}`));
+          }
+        } else {
+          diffLog.push(chalk.green(`+ ${variableName}`));
+        }
+      } else if (currentEnvLocal[variableName]) {
+        diffLog.push(chalk.red(`- ${variableName}`));
+      }
+    }
+    Log.addNewLineIfNone();
+
     const skippedSecretVariables: string[] = [];
     const overridenSecretVariables: string[] = [];
 
@@ -146,5 +197,10 @@ export default class EnvPull extends EasCommand {
         )}.`
       );
     }
+
+    Log.addNewLineIfNone();
+    diffLog.forEach(line => {
+      Log.log(line);
+    });
   }
 }