test: test the default GCC version correctly

src/gcc/__tests__/gcc.test.ts

@@ -1,6 +1,7 @@
 import { execaSync } from "execa"
 import { chmod } from "fs/promises"
 import { addExeExt, join } from "patha"
+import { isUbuntu } from "../../utils/env/isUbuntu.js"
 import { ubuntuVersion } from "../../utils/env/ubuntu_version.js"
 import { cleanupTmpDir, setupTmpDir, testBin } from "../../utils/tests/test-helpers.js"
 import { getVersion } from "../../versions/versions.js"
@@ -14,13 +15,40 @@ describe("setup-gcc", () => {
   })
 
   it("should setup gcc", async () => {
-    const version = getVersion("gcc", undefined, await ubuntuVersion())
+    const ubuntuVersionOutput = await ubuntuVersion()
+    const version = getVersion("gcc", undefined, ubuntuVersionOutput)
     const installInfo = await setupGcc(version, directory, process.arch)
 
     let gpp = "g++"
-    if (process.platform !== "win32") {
-      gpp = `g++-${version}`
+    if (isUbuntu()) {
+      const ubuntuMajorVersion = ubuntuVersionOutput?.[0]
+      // https://packages.ubuntu.com/search?keywords=gcc
+      switch (ubuntuMajorVersion) {
+        case 26:
+        case 25:
+          gpp = "g++-14"
+          break
+        case 24:
+        case 23:
+          gpp = "g++-13"
+          break
+        case 22:
+        case 21:
+          gpp = "g++-11"
+          break
+        case 20:
+          gpp = "g++-9"
+          break
+        default: {
+          // ignore
+        }
+      }
+    } else if (process.platform === "darwin") {
+      // https://formulae.brew.sh/formula/gcc
+      // As of 3, Sep, 2024
+      gpp = "g++-14"
     }
+
     await testBin(gpp, ["--version"], installInfo?.binDir)
 
     expect(process.env.CC?.includes("gcc")).toBeTruthy()