Read failed test logs from file

rascal-vscode-extension/src/test/vscode-suite/utils.ts

@@ -27,7 +27,8 @@
 
 import { assert, expect } from "chai";
 import { createHash } from "crypto";
-import { readFile, stat, unlink, writeFile } from "fs/promises";
+import { existsSync } from "fs";
+import { readdir, readFile, stat, unlink, writeFile } from "fs/promises";
 import * as os from 'os';
 import path from "path/posix";
 import { env } from "process";
@@ -524,40 +525,72 @@ async function assureDebugLevelLoggingIsEnabled() {
 export function printRascalOutputOnFailure(channel: 'Language Parametric Rascal' | 'Rascal MPL') {
 
     const ZOOM_OUT_FACTOR = 5;
+    const N_LOG_LINES = 250;
+    // We guess some locations where the logs can be, since we cannot easily retrieve those from VS Code.
+    const TEST_STORAGE_DIRS = [
+        path.join(path.resolve(), "uitests"),    // typical CI path
+        path.join(os.tmpdir(), "vscode-uitests") // typical local path
+    ];
+
     afterEach("print output in case of failure", async function () {
         if (!this.currentTest || this.currentTest.state !== "failed") { return; }
-        const bbp = new BottomBarPanel();
-        try {
-            for (let z = 0; z < ZOOM_OUT_FACTOR; z++) {
-                await new Workbench().executeCommand('workbench.action.zoomOut');
-            }
-            await bbp.maximize();
-            console.log('**********************************************');
-            console.log('***** Rascal MPL output for the failed tests: ');
-            let textLines: WebElement[] = [];
-            let tries = 0;
-            while (textLines.length === 0 && tries < 3) {
-                await showRascalOutput(bbp, channel);
-                textLines = await ignoreFails(bbp.findElements(By.className('view-line'))) ?? [];
-                tries++;
-            }
-            if (textLines.length === 0) {
-                console.log("We could not capture the output lines");
-            }
 
-            for (const l of textLines) {
-                console.log(await l.getText());
+        console.log('**********************************************');
+        console.log(`***** ${channel} output for the failed tests: `);
+
+        let foundLogs = false;
+        for (const vsCodeDir of TEST_STORAGE_DIRS) {
+            try {
+                const logDir = path.join(vsCodeDir, "settings", "logs");
+                if (existsSync(logDir)) {
+                    for (const entry of await readdir(logDir, {recursive: true})) {
+                        if (entry.includes("usethesource.rascalmpl") && entry.includes(channel)) {
+                            console.log(`***** ${entry}`);
+                            const contents = await readFile(path.join(logDir, entry), {encoding: "utf-8"});
+                            console.log(contents.split('\n').splice(-N_LOG_LINES).join('\n'));
+                            foundLogs = true;
+                        }
+                    }
+                }
+            } catch (e) {
+                console.log(`Error capturing logs in ${vsCodeDir}: `, e);
             }
-        } catch (e) {
-            console.log('Error capturing output: ', e);
         }
-        finally {
-            console.log('*******End output*****************************');
-            for (let z = 0; z < ZOOM_OUT_FACTOR; z++) {
-                await new Workbench().executeCommand('workbench.action.zoomIn');
+
+        if (!foundLogs) {
+            // Fall back to legacy copy-from-VS Code approach if there were no log files.
+            const bbp = new BottomBarPanel();
+            try {
+                for (let z = 0; z < ZOOM_OUT_FACTOR; z++) {
+                    await new Workbench().executeCommand('workbench.action.zoomOut');
+                }
+                await bbp.maximize();
+                let textLines: WebElement[] = [];
+                let tries = 0;
+                while (textLines.length === 0 && tries < 3) {
+                    await showRascalOutput(bbp, channel);
+                    textLines = await ignoreFails(bbp.findElements(By.className('view-line'))) ?? [];
+                    tries++;
+                }
+                if (textLines.length === 0) {
+                    console.log("We could not capture the output lines");
+                }
+
+                for (const l of textLines) {
+                    console.log(await l.getText());
+                }
+            } catch (e) {
+                console.log('Error capturing output: ', e);
+            }
+            finally {
+                for (let z = 0; z < ZOOM_OUT_FACTOR; z++) {
+                    await new Workbench().executeCommand('workbench.action.zoomIn');
+                }
+                await bbp.closePanel();
             }
-            await bbp.closePanel();
         }
+
+        console.log('*******End output*****************************');
     });
 }