Address review feedback on the disk space check

Say "at or above" in the debug message logged when the check passes,
since the comparison accepts exactly the minimum.

Check each feature flag against the threshold its name declares, rather
than only exercising a few of them, so that a mistake in one of the
mappings cannot go unnoticed. Both sides of the boundary are needed to
pin a threshold down: a mapping to a lower value would still pass the
case at the limit, and one to a higher value would still fail the case
below it.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: henrymercer

lib/entry-points.js

@@ -1333,26 +1333,57 @@ checkOverlayEnablementMacro.serial(
   },
 );
 
-checkOverlayEnablementMacro.serial(
-  "Overlay-base database on default branch if runner disk space is above the limit lowered by a feature flag",
-  {
-    languages: [BuiltInLanguage.javascript],
-    features: [
-      Feature.OverlayAnalysis,
-      Feature.OverlayAnalysisCodeScanningJavascript,
-      Feature.OverlayAnalysisMinDisk10Gb,
-    ],
-    isDefaultBranch: true,
-    diskUsage: {
-      numAvailableBytes: 11_000_000_000,
-      numTotalBytes: 100_000_000_000,
+// Check that each feature flag lowers the limit to the threshold that its name
+// declares. Both sides of the boundary are needed to pin the threshold down: a
+// mapping to a lower value would still pass the case at the limit, and one to a
+// higher value would still fail the case below it.
+for (const [feature, thresholdGb] of [
+  [Feature.OverlayAnalysisMinDisk8Gb, 8],
+  [Feature.OverlayAnalysisMinDisk9Gb, 9],
+  [Feature.OverlayAnalysisMinDisk10Gb, 10],
+  [Feature.OverlayAnalysisMinDisk11Gb, 11],
+  [Feature.OverlayAnalysisMinDisk12Gb, 12],
+  [Feature.OverlayAnalysisMinDisk13Gb, 13],
+] as Array<[Feature, number]>) {
+  const features = [
+    Feature.OverlayAnalysis,
+    Feature.OverlayAnalysisCodeScanningJavascript,
+    feature,
+  ];
+
+  checkOverlayEnablementMacro.serial(
+    `Overlay-base database on default branch if ${feature} is enabled and runner disk space is at its limit`,
+    {
+      languages: [BuiltInLanguage.javascript],
+      features,
+      isDefaultBranch: true,
+      diskUsage: {
+        numAvailableBytes: thresholdGb * 1_000_000_000,
+        numTotalBytes: 100_000_000_000,
+      },
     },
-  },
-  {
-    overlayDatabaseMode: OverlayDatabaseMode.OverlayBase,
-    useOverlayDatabaseCaching: true,
-  },
-);
+    {
+      overlayDatabaseMode: OverlayDatabaseMode.OverlayBase,
+      useOverlayDatabaseCaching: true,
+    },
+  );
+
+  checkOverlayEnablementMacro.serial(
+    `No overlay-base database on default branch if ${feature} is enabled and runner disk space is below its limit`,
+    {
+      languages: [BuiltInLanguage.javascript],
+      features,
+      isDefaultBranch: true,
+      diskUsage: {
+        numAvailableBytes: thresholdGb * 1_000_000_000 - 1_000_000,
+        numTotalBytes: 100_000_000_000,
+      },
+    },
+    {
+      disabledReason: OverlayDisabledReason.InsufficientDiskSpace,
+    },
+  );
+}
 
 checkOverlayEnablementMacro.serial(
   "Overlay-base database on default branch if runner disk space is exactly at the lowest limit enabled by a feature flag",

src/config-utils.test.ts

@@ -630,8 +630,8 @@ function runnerHasSufficientDiskSpace(
   }
 
   logger.debug(
-    `Disk space available for CodeQL analysis is ${diskSpaceMb} MB, which is above the minimum ` +
-      `of ${minimumDiskSpaceMb} MB.`,
+    `Disk space available for CodeQL analysis is ${diskSpaceMb} MB, which is at or above the ` +
+      `minimum of ${minimumDiskSpaceMb} MB.`,
   );
   return true;
 }