#include <bits/stdc++.h>
using namespace std;
const int p = 1e9 + 7;
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int Case;
    cin >> Case;
    while (Case--) {
        int n;
        cin >> n;
        vector<int> a(n);
        bool valid = 1;
        for (int i = 0; i < n; ++i) {
            cin >> a[i];
            if (a[i] < 0 || a[i] >= n) valid = 0;
            if (i && a[i] < a[i - 1]) valid = 0;
        }
        if (!valid) { cout << 0 << '\n'; continue; }
        int ans = 1;
        for (int i = 1; i < n; ++i) {
            if (a[i] > a[i - 1]) ans = ans * 2 % p;
            else {
                // i + 1 number a[i] + 1 number
                if (a[i] + 1 - i <= 0) ans = 0;
                ans = 1ll * ans * (a[i] + 1 - i) % p;
            }
        }
        cout << ans << '\n';
    }
    return 0;
}