RUST-1539 Restructure and refine contents of Evergreen configuration (#939)

Author: isabelatkinson

.evergreen/cargo-test.sh

@@ -5,32 +5,26 @@ TEST_OPTIONS=()
 FEATURE_FLAGS=()
 CARGO_RESULT=0
 
-use_async_runtime() {
-    if [ "${ASYNC_RUNTIME}" = "async-std" ]; then
-        FEATURE_FLAGS+=("async-std-runtime")
-        CARGO_OPTIONS+=("--no-default-features")
-    elif [ "${ASYNC_RUNTIME}" != "tokio" ]; then
-        echo "invalid async runtime: ${ASYNC_RUNTIME}" >&2
-        exit 1
-    fi
+join_by() {
+  local IFS="$1"
+  shift
+  echo "$*"
 }
 
-join_by() { local IFS="$1"; shift; echo "$*"; }
-
 cargo_test_options() {
-    local FILTERED=()
-    for FEAT in "${FEATURE_FLAGS[@]}"; do
-        [[ "${FEAT}" != "" ]] && FILTERED+=("${FEAT}")
-    done
-    local FEATURE_OPTION=""
-    if (( ${#FILTERED[@]} != 0 )); then
-        FEATURE_OPTION="--features $(join_by , "${FILTERED[@]}")"
-    fi
-    echo $1 ${CARGO_OPTIONS[@]} ${FEATURE_OPTION} -- ${TEST_OPTIONS[@]}
+  local FILTERED=()
+  for FEAT in "${FEATURE_FLAGS[@]}"; do
+    [[ "${FEAT}" != "" ]] && FILTERED+=("${FEAT}")
+  done
+  local FEATURE_OPTION=""
+  if ((${#FILTERED[@]} != 0)); then
+    FEATURE_OPTION="--features $(join_by , "${FILTERED[@]}")"
+  fi
+  echo $1 ${CARGO_OPTIONS[@]} ${FEATURE_OPTION} -- ${TEST_OPTIONS[@]}
 }
 
 cargo_test() {
-    RUST_BACKTRACE=1 cargo nextest run --profile ci $(cargo_test_options $1)
-    (( CARGO_RESULT = ${CARGO_RESULT} || $? ))
-    mv target/nextest/ci/junit.xml $2
+  RUST_BACKTRACE=1 cargo nextest run --profile ci $(cargo_test_options $1)
+  ((CARGO_RESULT = ${CARGO_RESULT} || $?))
+  mv target/nextest/ci/junit.xml $2
 }

.evergreen/check-cargo-deny.sh

@@ -6,4 +6,4 @@ set -o xtrace
 source ./.evergreen/env.sh
 
 cargo install --locked cargo-deny
-cargo deny --all-features check
+cargo deny --all-features check

.evergreen/check-clippy.sh

@@ -11,5 +11,5 @@ CLIPPY_VERSION=1.71.0
 rustup install $CLIPPY_VERSION
 
 for ((i = 0; i < ${#FEATURE_COMBINATIONS[@]}; i++)); do
-    cargo +$CLIPPY_VERSION clippy --all-targets ${FEATURE_COMBINATIONS[$i]}  -p mongodb -- -D warnings
+  cargo +$CLIPPY_VERSION clippy --all-targets ${FEATURE_COMBINATIONS[$i]} -p mongodb -- -D warnings
 done

.evergreen/check-rustdoc.sh

@@ -7,7 +7,7 @@ source ./.evergreen/env.sh
 # docs.rs builds the driver on a read-only file system. to create a more realistic environment, we first
 # build the driver to ensure we have all the deps already in src, and then limit the permissions on that directory
 # and rebuild the docs.
-# this is to help us avoid introducing problems like those described here 
+# this is to help us avoid introducing problems like those described here
 # https://docs.rs/about/builds#read-only-directories where we or a dependency modify source code during the
 # build process.
 

.evergreen/compile-only.sh

@@ -4,16 +4,17 @@ set -o errexit
 set -o xtrace
 
 source ./.evergreen/env.sh
-rustup update $RUST_VERSION
 
-# pin dependencies who have bumped their MSRVs to > ours in recent releases.
-if [  "$MSRV" = "true" ]; then
-    cp .evergreen/MSRV-Cargo.lock Cargo.lock
+# Install the MSRV and pin dependencies who have bumped their MSRVs to > ours in recent releases.
+if [ "$RUST_VERSION" != "" ]; then
+  rustup toolchain install $RUST_VERSION
+  TOOLCHAIN="+${RUST_VERSION}"
+  cp .evergreen/MSRV-Cargo.lock Cargo.lock
 fi
 
 source ./.evergreen/feature-combinations.sh
 
-# build with all available features to ensure all optional dependencies are brought in too.
+# Test compilation with all feature combinations.
 for ((i = 0; i < ${#FEATURE_COMBINATIONS[@]}; i++)); do
-    rustup run $RUST_VERSION cargo build ${FEATURE_COMBINATIONS[$i]}
+  cargo $TOOLCHAIN build ${FEATURE_COMBINATIONS[$i]}
 done