Give an error message when the wasm test fails (#482)

ci/github.sh

@@ -102,9 +102,14 @@ test_wasm() {
 }
 
 test_wasm_simple() {
-    now=$(date +%s)
-    tz=$(date +%z)
-    runt env TZ="$tz" NOW="$now" wasm-pack test --node -- --features wasmbind
+    if ! runt env TZ="$(date +%z)" NOW="$(date +%s)" wasm-pack test --node -- --features wasmbind ; then
+        # sometimes on github the initial build takes 8-10 minutes, and we
+        # check that the time makes sense inside the test by approximately
+        # comparing it to the env var,
+        #
+        # so re-run the test in case it took too long
+        runt env TZ="$(date +%z)" NOW="$(date +%s)" wasm-pack test --node -- --features wasmbind
+    fi
 }
 
 main "$@"

tests/wasm.rs

@@ -11,9 +11,18 @@ mod test {
         let utc: DateTime<Utc> = Utc::now();
         let local: DateTime<Local> = Local::now();
 
-        // Ensure time fetched is correct
-        let actual = Utc.datetime_from_str(&env!("NOW"), "%s").unwrap();
-        assert!(utc - actual < chrono::Duration::minutes(5));
+        // Ensure time set by the test script is correct
+        let now = env!("NOW");
+        let actual = Utc.datetime_from_str(&now, "%s").unwrap();
+        let diff = utc - actual;
+        assert!(
+            diff < chrono::Duration::minutes(5),
+            "expected {} - {} == {} < 5m (env var: {})",
+            utc,
+            actual,
+            diff,
+            now,
+        );
 
         let tz = env!("TZ");
         eprintln!("testing with tz={}", tz);