Merge pull request #470 from ndycode/fix/bump-version-fallback-468

fix: bump version fallback to 1.18.3 to unblock Gemini 3.1 Pro

docs/TROUBLESHOOTING.md

@@ -84,6 +84,39 @@ The correct key is `plugin` (singular):
 
 **Not** `"plugins"` (will cause "Unrecognized key" error).
 
+### "Invalid SemVer: beta"
+
+**Error:**
+```
+Invalid SemVer
+{
+  "name": "UnknownError",
+  "data": {
+    "message": "Error: Invalid SemVer: beta ... isOutdated (src/bun/registry.ts:...)"
+  }
+}
+```
+
+**Why this happens:** OpenCode's cache may keep the plugin dependency as a dist-tag (`"beta"`) in `~/.cache/opencode/package.json` and `~/.cache/opencode/bun.lock`. Some OpenCode versions compare plugin versions as strict semver and fail on non-numeric tags.
+
+**Fix (recommended):** Re-resolve the dependency in OpenCode cache so it is pinned to a real version.
+
+**macOS / Linux:**
+```bash
+cd ~/.cache/opencode
+bun add opencode-antigravity-auth@latest
+```
+
+**Windows (PowerShell):**
+```powershell
+Set-Location "$env:USERPROFILE\.cache\opencode"
+bun add opencode-antigravity-auth@latest
+```
+
+Then restart OpenCode.
+
+> If you intentionally run beta channel, use `bun add opencode-antigravity-auth@beta` instead.
+
 ---
 
 ## Gemini CLI Permission Error

src/constants.ts

@@ -70,7 +70,7 @@ export const GEMINI_CLI_ENDPOINT = ANTIGRAVITY_ENDPOINT_PROD;
  */
 export const ANTIGRAVITY_DEFAULT_PROJECT_ID = "rising-fact-p41fc";
 
-const ANTIGRAVITY_VERSION_FALLBACK = "1.15.8";
+export const ANTIGRAVITY_VERSION_FALLBACK = "1.18.3";
 let antigravityVersion = ANTIGRAVITY_VERSION_FALLBACK;
 let versionLocked = false;
 

src/plugin/version.test.ts

@@ -0,0 +1,112 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest"
+
+/**
+ * Regression tests for the version fallback mechanism.
+ *
+ * Issue #468: On WSL2/AlmaLinux with strict firewall rules, both the
+ * auto-updater API and changelog fetch fail. The plugin then uses the
+ * hardcoded fallback version in User-Agent headers. If the fallback is
+ * too old, the backend rejects requests for newer models (e.g., Gemini 3.1 Pro)
+ * with "not available on this version".
+ *
+ * These tests verify the fallback is current and that the
+ * network-failure path correctly uses it.
+ */
+
+// Reset module state between tests so versionLocked starts fresh
+beforeEach(() => {
+  vi.resetModules()
+})
+
+afterEach(() => {
+  vi.unstubAllGlobals()
+})
+
+describe("ANTIGRAVITY_VERSION_FALLBACK", () => {
+  it("defaults to the exported fallback constant", async () => {
+    const { ANTIGRAVITY_VERSION_FALLBACK, getAntigravityVersion } = await import("../constants.ts")
+    expect(getAntigravityVersion()).toBe(ANTIGRAVITY_VERSION_FALLBACK)
+  })
+
+  it("is at least 1.18.0 to support Gemini 3.1 Pro", async () => {
+    const { getAntigravityVersion } = await import("../constants.ts")
+    const [major, minor] = getAntigravityVersion().split(".").map(Number)
+    expect(major).toBeGreaterThanOrEqual(1)
+    if (major === 1) expect(minor).toBeGreaterThanOrEqual(18)
+  })
+})
+
+describe("setAntigravityVersion", () => {
+  it("updates the version on first call", async () => {
+    const { getAntigravityVersion, setAntigravityVersion } = await import("../constants.ts")
+    setAntigravityVersion("2.0.0")
+    expect(getAntigravityVersion()).toBe("2.0.0")
+  })
+
+  it("locks after first call — subsequent calls are ignored", async () => {
+    const { getAntigravityVersion, setAntigravityVersion } = await import("../constants.ts")
+    setAntigravityVersion("2.0.0")
+    setAntigravityVersion("3.0.0")
+    expect(getAntigravityVersion()).toBe("2.0.0")
+  })
+})
+
+describe("initAntigravityVersion — network failure path", () => {
+  it("falls back to hardcoded version when both fetches throw", async () => {
+    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(new Error("network unreachable")))
+
+    const { ANTIGRAVITY_VERSION_FALLBACK, getAntigravityVersion } = await import("../constants.ts")
+    const { initAntigravityVersion } = await import("./version.ts")
+    await initAntigravityVersion()
+
+    expect(getAntigravityVersion()).toBe(ANTIGRAVITY_VERSION_FALLBACK)
+  })
+
+  it("falls back to hardcoded version when both fetches return non-ok", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({ ok: false, status: 503, text: async () => "" }),
+    )
+
+    const { ANTIGRAVITY_VERSION_FALLBACK, getAntigravityVersion } = await import("../constants.ts")
+    const { initAntigravityVersion } = await import("./version.ts")
+    await initAntigravityVersion()
+
+    expect(getAntigravityVersion()).toBe(ANTIGRAVITY_VERSION_FALLBACK)
+  })
+
+  it("uses API version when auto-updater responds", async () => {
+    vi.stubGlobal(
+      "fetch",
+      vi.fn().mockResolvedValue({ ok: true, text: async () => "1.19.0" }),
+    )
+
+    const { getAntigravityVersion } = await import("../constants.ts")
+    const { initAntigravityVersion } = await import("./version.ts")
+    await initAntigravityVersion()
+
+    expect(getAntigravityVersion()).toBe("1.19.0")
+  })
+
+  it("fallback version appears in User-Agent header", async () => {
+    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(new Error("timeout")))
+
+    const { ANTIGRAVITY_VERSION_FALLBACK, getAntigravityHeaders } = await import("../constants.ts")
+    const { initAntigravityVersion } = await import("./version.ts")
+    await initAntigravityVersion()
+
+    const headers = getAntigravityHeaders()
+    expect(headers["User-Agent"]).toContain(`Antigravity/${ANTIGRAVITY_VERSION_FALLBACK}`)
+  })
+
+  it("fallback version appears in randomized antigravity headers", async () => {
+    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(new Error("timeout")))
+
+    const { ANTIGRAVITY_VERSION_FALLBACK, getRandomizedHeaders } = await import("../constants.ts")
+    const { initAntigravityVersion } = await import("./version.ts")
+    await initAntigravityVersion()
+
+    const headers = getRandomizedHeaders("antigravity")
+    expect(headers["User-Agent"]).toContain(ANTIGRAVITY_VERSION_FALLBACK)
+  })
+})