From bbc3ec54c785225068477187d16ac145f74c789c Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Fri, 26 Jun 2020 12:48:44 +1200
Subject: [PATCH] CI: Fetch and cache Sapling parameters for tests

---
 .github/workflows/ci.yml                 | 15 +++++++++++++++
 .travis.yml                              | 19 -------------------
 zcash_proofs/Cargo.toml                  |  4 ++++
 zcash_proofs/examples/get-params-path.rs |  7 +++++++
 zcash_proofs/src/lib.rs                  |  2 +-
 5 files changed, 27 insertions(+), 20 deletions(-)
 delete mode 100644 .travis.yml
 create mode 100644 zcash_proofs/examples/get-params-path.rs

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7724e4ab2..3735bf199 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -50,6 +50,21 @@ jobs:
         with:
           toolchain: 1.40.0
           override: true
+
+      - name: Fetch path to Zcash parameters
+        working-directory: ./zcash_proofs
+        run: echo "::set-env name=ZCASH_PARAMS::$(cargo run --release --example get-params-path --features directories)"
+      - name: Cache Zcash parameters
+        id: cache-params
+        uses: actions/cache@v2
+        with:
+          path: ${{ env.ZCASH_PARAMS }}
+          key: ${{ runner.os }}-params
+      - name: Fetch Zcash parameters
+        if: steps.cache-params.outputs.cache-hit != 'true'
+        working-directory: ./zcash_proofs
+        run: cargo run --release --example download-params --features download-params
+
       - name: cargo fetch
         uses: actions-rs/cargo@v1
         with:
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index e77c9e296..000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,19 +0,0 @@
-language: rust
-rust:
-  - 1.40.0
-
-cache: cargo
-
-before_script:
-  - rustup component add rustfmt
-
-script:
-  - cargo build --verbose --release --all
-  - cargo fmt --all -- --check
-  - cargo test --verbose --release --all
-  - cargo test --verbose --release --all -- --ignored
-
-before_cache:
-  - rm -rf "$TRAVIS_HOME/.cargo/registry/src"
-  - cargo install cargo-update || echo "cargo-update already installed"
-  - cargo install-update -a # update outdated cached binaries
diff --git a/zcash_proofs/Cargo.toml b/zcash_proofs/Cargo.toml
index 62d568cef..4a58e9dfb 100644
--- a/zcash_proofs/Cargo.toml
+++ b/zcash_proofs/Cargo.toml
@@ -31,6 +31,10 @@ download-params = ["minreq"]
 local-prover = ["directories"]
 multicore = ["bellman/multicore"]
 
+[[example]]
+name = "get-params-path"
+required-features = ["directories"]
+
 [[example]]
 name = "download-params"
 required-features = ["download-params"]
diff --git a/zcash_proofs/examples/get-params-path.rs b/zcash_proofs/examples/get-params-path.rs
new file mode 100644
index 000000000..224b2f5ea
--- /dev/null
+++ b/zcash_proofs/examples/get-params-path.rs
@@ -0,0 +1,7 @@
+fn main() {
+    if let Some(path) = zcash_proofs::default_params_folder() {
+        if let Some(path) = path.to_str() {
+            println!("{}", path);
+        }
+    }
+}
diff --git a/zcash_proofs/src/lib.rs b/zcash_proofs/src/lib.rs
index e952be6be..e14a26953 100644
--- a/zcash_proofs/src/lib.rs
+++ b/zcash_proofs/src/lib.rs
@@ -39,7 +39,7 @@ const DOWNLOAD_URL: &str = "https://download.z.cash/downloads";
 
 /// Returns the default folder that the Zcash proving parameters are located in.
 #[cfg(feature = "directories")]
-fn default_params_folder() -> Option<PathBuf> {
+pub fn default_params_folder() -> Option<PathBuf> {
     BaseDirs::new().map(|base_dirs| {
         if cfg!(any(windows, target_os = "macos")) {
             base_dirs.data_dir().join("ZcashParams")