diff --git a/implementations/javascript/packages/core/test/test-utils.ts b/implementations/javascript/packages/core/test/test-utils.ts
index 251864d..73c6fd8 100644
--- a/implementations/javascript/packages/core/test/test-utils.ts
+++ b/implementations/javascript/packages/core/test/test-utils.ts
@@ -28,7 +28,7 @@ expect.extend({
                 return { message: () => preserves`expected an exception not matching the filter`,
                          pass: true };
             } else {
-                return { message: () => preserves`expected an exception matching the filter: ${e.constructor.name}`,
+                return { message: () => preserves`expected an exception matching the filter: ${(e as any)?.constructor?.name}`,
                          pass: false };
             }
         }
diff --git a/implementations/javascript/packages/schema/test/checker.test.ts b/implementations/javascript/packages/schema/test/checker.test.ts
index 35920c5..cf455e8 100644
--- a/implementations/javascript/packages/schema/test/checker.test.ts
+++ b/implementations/javascript/packages/schema/test/checker.test.ts
@@ -32,8 +32,8 @@ describe('checker', () => {
                        definitions: {
                          ExtensibleRecord:
                            <rec <lit foo>
-                                <tuple* [<named a <atom String>>, <named b <atom String>>]
-                                        <named extra <seqof any>>>>}}>`).next());
+                                <tuplePrefix [<named a <atom String>>, <named b <atom String>>]
+                                             <named extra <seqof any>>>>}}>`).next());
         });
         it('non-invertibility tail', () => {
             expect(() => readSchema(
@@ -51,11 +51,11 @@ describe('checker', () => {
             expect(() => readSchema('version 1 . A = { x: @a string , y: @a string }.'))
                 .toThrow(/duplicate binding named "a" in entry y in dictionary in A/);
         });
-        it('complains about duplicates in tuple*s', () => {
+        it('complains about duplicates in tuplePrefixes', () => {
             expect(() => readSchema('version 1 . A = [@a string @b string @a int @rest any ...].'))
                 .toThrow(/duplicate binding named "a" in item 2 of A/);
         });
-        it('complains about duplicates in tuple* tails', () => {
+        it('complains about duplicates in tuplePrefix tails', () => {
             expect(() => readSchema('version 1 . A = [@a string @b string @c int @a any ...].'))
                 .toThrow(/duplicate binding named "a" in tail of A/);
         });
@@ -113,7 +113,7 @@ describe('checker', () => {
                     `version 1 .
                      AAA = <a @a string @a int>.
                      ABC = <a @b string @c int>.
-                     A = @x AAA & @y ABC.`))
+                     A = @x AAA & @y ABC .`))
                     .toThrow(/in item 1 of fields of AAA/);
             });
             it('is OK with seeming- but non-duplicates across named branches', () => {
@@ -121,7 +121,7 @@ describe('checker', () => {
                     `version 1 .
                      AAA = <a @a string @b int>.
                      ABC = <a @a string @c int>.
-                     A = @x AAA & @y ABC.`))
+                     A = @x AAA & @y ABC .`))
                     .not.toBeNull();
             });
             it('complains about duplicate branch names', () => {
@@ -129,7 +129,7 @@ describe('checker', () => {
                     `version 1 .
                      AAB = <a @a string @b int>.
                      ACD = <a @c string @d int>.
-                     A = @x AAB & @x ACD.`))
+                     A = @x AAB & @x ACD .`))
                     .toThrow(/in A/);
             });
         });
diff --git a/implementations/javascript/packages/schema/test/test-utils.ts b/implementations/javascript/packages/schema/test/test-utils.ts
index 42a8f09..d0b6766 100644
--- a/implementations/javascript/packages/schema/test/test-utils.ts
+++ b/implementations/javascript/packages/schema/test/test-utils.ts
@@ -27,7 +27,7 @@ expect.extend({
                 return { message: () => preserves`expected an exception not matching the filter`,
                          pass: true };
             } else {
-                return { message: () => preserves`expected an exception matching the filter: ${e.constructor.name}`,
+                return { message: () => preserves`expected an exception matching the filter: ${(e as any)?.constructor?.name}`,
                          pass: false };
             }
         }