From be9b01acc08dfbd46e5fb11952159114aad26cb6 Mon Sep 17 00:00:00 2001
From: Ian Clanton-Thuon <iclanton@users.noreply.github.com>
Date: Wed, 14 Jun 2023 11:49:13 -0700
Subject: [PATCH] Fix an issue where Rush would attempt to open a project's log
 file for writing twice.

---
 .../fix-log-double-open_2023-06-14-18-49.json | 10 ++++
 .../logic/operations/ProjectLogWritable.ts    | 52 +++++++++----------
 .../logic/operations/ShellOperationRunner.ts  |  1 +
 3 files changed, 37 insertions(+), 26 deletions(-)
 create mode 100644 common/changes/@microsoft/rush/fix-log-double-open_2023-06-14-18-49.json

diff --git a/common/changes/@microsoft/rush/fix-log-double-open_2023-06-14-18-49.json b/common/changes/@microsoft/rush/fix-log-double-open_2023-06-14-18-49.json
new file mode 100644
index 00000000000..83acdc6e026
--- /dev/null
+++ b/common/changes/@microsoft/rush/fix-log-double-open_2023-06-14-18-49.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/rush",
+      "comment": "Fix an issue where Rush would attempt to open a project's log file for writing twice.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@microsoft/rush"
+}
\ No newline at end of file
diff --git a/libraries/rush-lib/src/logic/operations/ProjectLogWritable.ts b/libraries/rush-lib/src/logic/operations/ProjectLogWritable.ts
index f9fb3da0373..adf338a1fbd 100644
--- a/libraries/rush-lib/src/logic/operations/ProjectLogWritable.ts
+++ b/libraries/rush-lib/src/logic/operations/ProjectLogWritable.ts
@@ -60,39 +60,39 @@ export class ProjectLogWritable extends TerminalWritable {
     }
 
     const projectFolder: string = this._project.projectFolder;
-    const {
-      logPath: legacyLogPath,
-      errorLogPath: legacyErrorLogPath,
-      relativeLogPath: legacyRelativeLogPath,
-      relativeErrorLogPath: legacyRelativeErrorLogPath
-    } = getLogFilePaths(projectFolder, 'build');
+    // Delete the legacy logs
+    const { logPath: legacyLogPath, errorLogPath: legacyErrorLogPath } = getLogFilePaths(
+      projectFolder,
+      'build'
+    );
+    FileSystem.deleteFile(legacyLogPath);
+    FileSystem.deleteFile(legacyErrorLogPath);
+
     // If the phased commands experiment is enabled, put logs under `rush-logs`
+    let logFolder: string | undefined;
     if (project.rushConfiguration.experimentsConfiguration.configuration.phasedCommands) {
-      // Delete the legacy logs
-      FileSystem.deleteFile(legacyLogPath);
-      FileSystem.deleteFile(legacyErrorLogPath);
-
       const logPathPrefix: string = `${projectFolder}/${RushConstants.rushLogsFolderName}`;
       FileSystem.ensureFolder(logPathPrefix);
+      logFolder = RushConstants.rushLogsFolderName;
+    }
 
-      const { logPath, errorLogPath, relativeLogPath, relativeErrorLogPath } = getLogFilePaths(
-        projectFolder,
-        logFilenameIdentifier,
-        RushConstants.rushLogsFolderName
-      );
-      this.logPath = logPath;
-      this.errorLogPath = errorLogPath;
-      this.relativeLogPath = relativeLogPath;
-      this.relativeErrorLogPath = relativeErrorLogPath;
-    } else {
-      this.logPath = legacyLogPath;
-      this.errorLogPath = legacyErrorLogPath;
-      this.relativeLogPath = legacyRelativeLogPath;
-      this.relativeErrorLogPath = legacyRelativeErrorLogPath;
+    const { logPath, errorLogPath, relativeLogPath, relativeErrorLogPath } = getLogFilePaths(
+      projectFolder,
+      logFilenameIdentifier,
+      logFolder
+    );
+    this.logPath = logPath;
+    this.errorLogPath = errorLogPath;
+    this.relativeLogPath = relativeLogPath;
+    this.relativeErrorLogPath = relativeErrorLogPath;
+
+    if (legacyLogPath !== this.logPath) {
+      FileSystem.deleteFile(this.logPath);
     }
 
-    FileSystem.deleteFile(this.logPath);
-    FileSystem.deleteFile(this.errorLogPath);
+    if (legacyErrorLogPath !== this.errorLogPath) {
+      FileSystem.deleteFile(this.errorLogPath);
+    }
 
     this._logWriter = FileWriter.open(this.logPath);
   }
diff --git a/libraries/rush-lib/src/logic/operations/ShellOperationRunner.ts b/libraries/rush-lib/src/logic/operations/ShellOperationRunner.ts
index e0fcfd9269f..9a909ae10c7 100644
--- a/libraries/rush-lib/src/logic/operations/ShellOperationRunner.ts
+++ b/libraries/rush-lib/src/logic/operations/ShellOperationRunner.ts
@@ -142,6 +142,7 @@ export class ShellOperationRunner implements IOperationRunner {
   private async _executeAsync(context: IOperationRunnerContext): Promise<OperationStatus> {
     // Only open the *.cache.log file(s) if the cache is enabled.
     const cacheProjectLogWritable: ProjectLogWritable | undefined = this._buildCacheConfiguration
+      ?.buildCacheEnabled
       ? new ProjectLogWritable(
           this._rushProject,
           context.collatedWriter.terminal,