diff --git a/src/harness/virtualFileSystemWithWatch.ts b/src/harness/virtualFileSystemWithWatch.ts
index 13b87e1c91a..ffb1e19f653 100644
--- a/src/harness/virtualFileSystemWithWatch.ts
+++ b/src/harness/virtualFileSystemWithWatch.ts
@@ -11,7 +11,7 @@ interface Number { toExponential: any; }
 interface Object {}
 interface RegExp {}
 interface String { charAt: any; }
-interface Array<T> {}`
+interface Array<T> { length: number; [n: number]: T; }`
     };
 
     export const safeList = {
diff --git a/src/testRunner/tsconfig.json b/src/testRunner/tsconfig.json
index e7ff655ce10..c395b05e154 100644
--- a/src/testRunner/tsconfig.json
+++ b/src/testRunner/tsconfig.json
@@ -93,6 +93,7 @@
         "unittests/services/transpile.ts",
         "unittests/tsbuild/amdModulesWithOut.ts",
         "unittests/tsbuild/containerOnlyReferenced.ts",
+        "unittests/tsbuild/demo.ts",
         "unittests/tsbuild/emptyFiles.ts",
         "unittests/tsbuild/graphOrdering.ts",
         "unittests/tsbuild/inferredTypeFromTransitiveModule.ts",
diff --git a/src/testRunner/unittests/tsbuild/demo.ts b/src/testRunner/unittests/tsbuild/demo.ts
new file mode 100644
index 00000000000..ae34f033b79
--- /dev/null
+++ b/src/testRunner/unittests/tsbuild/demo.ts
@@ -0,0 +1,80 @@
+namespace ts {
+    describe("unittests:: tsbuild:: on demo project", () => {
+        let projFs: vfs.FileSystem;
+        const { time } = getTime();
+
+        before(() => {
+            projFs = loadProjectFromDisk("tests/projects/demo", time);
+        });
+
+        after(() => {
+            projFs = undefined!; // Release the contents
+        });
+
+        function coreOutputs(): string[] {
+            return [
+                "/src/lib/core/utilities.js",
+                "/src/lib/core/utilities.d.ts",
+                "/src/lib/core/tsconfig.tsbuildinfo"
+            ];
+        }
+
+        function animalOutputs(): string[] {
+            return [
+                "/src/lib/animals/animal.js",
+                "/src/lib/animals/animal.d.ts",
+                "/src/lib/animals/index.js",
+                "/src/lib/animals/index.d.ts",
+                "/src/lib/animals/dog.js",
+                "/src/lib/animals/dog.d.ts",
+                "/src/lib/animals/tsconfig.tsbuildinfo"
+            ];
+        }
+
+        function zooOutputs(): string[] {
+            return [
+                "/src/lib/zoo/zoo.js",
+                "/src/lib/zoo/zoo.d.ts",
+                "/src/lib/zoo/tsconfig.tsbuildinfo"
+            ];
+        }
+
+        interface VerifyBuild {
+            modifyDiskLayout: (fs: vfs.FileSystem) => void;
+            expectedExitStatus: ExitStatus;
+            expectedDiagnostics: fakes.ExpectedDiagnostic[];
+            expectedOutputs: readonly string[];
+            notExpectedOutputs: readonly string[];
+        }
+
+        function verifyBuild({ modifyDiskLayout, expectedExitStatus, expectedDiagnostics, expectedOutputs, notExpectedOutputs }: VerifyBuild) {
+            const fs = projFs.shadow();
+            const host = new fakes.SolutionBuilderHost(fs);
+            modifyDiskLayout(fs);
+            const builder = createSolutionBuilder(host, ["/src/tsconfig.json"], { verbose: true });
+            const exitStatus = builder.build();
+            assert.equal(exitStatus, expectedExitStatus);
+            host.assertDiagnosticMessages(...expectedDiagnostics);
+            verifyOutputsPresent(fs, expectedOutputs);
+            verifyOutputsAbsent(fs, notExpectedOutputs);
+        }
+
+        it("in master branch with everything setup correctly, reports no error", () => {
+            verifyBuild({
+                modifyDiskLayout: noop,
+                expectedExitStatus: ExitStatus.Success,
+                expectedDiagnostics: [
+                    getExpectedDiagnosticForProjectsInBuild("src/core/tsconfig.json", "src/animals/tsconfig.json", "src/zoo/tsconfig.json", "src/tsconfig.json"),
+                    [Diagnostics.Project_0_is_out_of_date_because_output_file_1_does_not_exist, "src/core/tsconfig.json", "src/lib/core/utilities.js"],
+                    [Diagnostics.Building_project_0, "/src/core/tsconfig.json"],
+                    [Diagnostics.Project_0_is_out_of_date_because_output_file_1_does_not_exist, "src/animals/tsconfig.json", "src/lib/animals/animal.js"],
+                    [Diagnostics.Building_project_0, "/src/animals/tsconfig.json"],
+                    [Diagnostics.Project_0_is_out_of_date_because_output_file_1_does_not_exist, "src/zoo/tsconfig.json", "src/lib/zoo/zoo.js"],
+                    [Diagnostics.Building_project_0, "/src/zoo/tsconfig.json"]
+                ],
+                expectedOutputs: [...coreOutputs(), ...animalOutputs(), ...zooOutputs()],
+                notExpectedOutputs: emptyArray
+            });
+        });
+    });
+}
diff --git a/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/incremental-declaration-changes/inferred-type-from-transitive-module.js b/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/incremental-declaration-changes/inferred-type-from-transitive-module.js
index c9334a7bcc9..0c32ba7c167 100644
--- a/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/incremental-declaration-changes/inferred-type-from-transitive-module.js
+++ b/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/incremental-declaration-changes/inferred-type-from-transitive-module.js
@@ -31,8 +31,8 @@ export declare const lazyBar: LazyAction<() => void, typeof import("./lazyIndex"
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../bar.ts": {
         "version": "747071916",
diff --git a/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/initial-Build/inferred-type-from-transitive-module.js b/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/initial-Build/inferred-type-from-transitive-module.js
index 88e0b710bb4..2a6aee9c8db 100644
--- a/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/initial-Build/inferred-type-from-transitive-module.js
+++ b/tests/baselines/reference/tsbuild/inferredTypeFromTransitiveModule/initial-Build/inferred-type-from-transitive-module.js
@@ -69,8 +69,8 @@ exports.bar = bar_1.default;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../bar.ts": {
         "version": "5936740878",
diff --git a/tests/baselines/reference/tsbuild/lateBoundSymbol/incremental-declaration-doesnt-change/interface-is-merged-and-contains-late-bound-member.js b/tests/baselines/reference/tsbuild/lateBoundSymbol/incremental-declaration-doesnt-change/interface-is-merged-and-contains-late-bound-member.js
index bfd580e9a99..84fe88219b1 100644
--- a/tests/baselines/reference/tsbuild/lateBoundSymbol/incremental-declaration-doesnt-change/interface-is-merged-and-contains-late-bound-member.js
+++ b/tests/baselines/reference/tsbuild/lateBoundSymbol/incremental-declaration-doesnt-change/interface-is-merged-and-contains-late-bound-member.js
@@ -22,8 +22,8 @@ type A = HKT<number>[typeof sym];
   "program": {
     "fileInfos": {
       "../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./src/globals.d.ts": {
         "version": "-1994196675",
diff --git a/tests/baselines/reference/tsbuild/lateBoundSymbol/initial-Build/interface-is-merged-and-contains-late-bound-member.js b/tests/baselines/reference/tsbuild/lateBoundSymbol/initial-Build/interface-is-merged-and-contains-late-bound-member.js
index d1e15d4ca99..afb887c35f8 100644
--- a/tests/baselines/reference/tsbuild/lateBoundSymbol/initial-Build/interface-is-merged-and-contains-late-bound-member.js
+++ b/tests/baselines/reference/tsbuild/lateBoundSymbol/initial-Build/interface-is-merged-and-contains-late-bound-member.js
@@ -15,8 +15,8 @@ var x = 10;
   "program": {
     "fileInfos": {
       "../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./src/globals.d.ts": {
         "version": "-1994196675",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/sample.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/sample.js
index cc92be46021..be4e09ba5b5 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/sample.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/sample.js
@@ -172,8 +172,8 @@ export class someClass { }
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
@@ -212,8 +212,8 @@ export class someClass { }
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-2069755619",
@@ -262,8 +262,8 @@ export class someClass { }
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-2069755619",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-declaration-option-changes.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-declaration-option-changes.js
index d58354590cb..bf28ddcc386 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-declaration-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-declaration-option-changes.js
@@ -21,8 +21,8 @@ export declare function multiply(a: number, b: number): number;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-esModuleInterop-option-changes.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-esModuleInterop-option-changes.js
index 28c559ee72a..e93ed540970 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-esModuleInterop-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-esModuleInterop-option-changes.js
@@ -37,8 +37,8 @@ exports.m = mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-logic-config-changes-declaration-dir.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-logic-config-changes-declaration-dir.js
index feefdf8f816..13204cdf566 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-logic-config-changes-declaration-dir.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-logic-config-changes-declaration-dir.js
@@ -25,8 +25,8 @@ export declare const m: typeof mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
@@ -76,8 +76,8 @@ export declare const m: typeof mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-module-option-changes.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-module-option-changes.js
index a73ad73c155..bda1af5741c 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-module-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-module-option-changes.js
@@ -31,8 +31,8 @@ define(["require", "exports"], function (require, exports) {
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-target-option-changes.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-target-option-changes.js
index 8e740f6a235..99721cc54b9 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-target-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-changes/when-target-option-changes.js
@@ -33,8 +33,8 @@ exports.multiply = multiply;
         "signature": "8926001564"
       },
       "../../lib/lib.esnext.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
diff --git a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-doesnt-change/sample.js b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-doesnt-change/sample.js
index ed2fb38595b..2b4b56abbf8 100644
--- a/tests/baselines/reference/tsbuild/sample1/incremental-declaration-doesnt-change/sample.js
+++ b/tests/baselines/reference/tsbuild/sample1/incremental-declaration-doesnt-change/sample.js
@@ -25,8 +25,8 @@ class someClass { }
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/sample.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/sample.js
index 75e23dfa0af..829dbe1718f 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/sample.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/sample.js
@@ -185,8 +185,8 @@ exports.multiply = multiply;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
@@ -370,8 +370,8 @@ sourceFile:index.ts
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
@@ -436,8 +436,8 @@ exports.m = mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-declaration-option-changes.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-declaration-option-changes.js
index 8a66ec9da1f..7c05255bfd1 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-declaration-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-declaration-option-changes.js
@@ -27,8 +27,8 @@ exports.multiply = multiply;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-esModuleInterop-option-changes.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-esModuleInterop-option-changes.js
index b6f0b53b89c..998c09d4710 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-esModuleInterop-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-esModuleInterop-option-changes.js
@@ -35,8 +35,8 @@ exports.multiply = multiply;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
@@ -96,8 +96,8 @@ exports.m = mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
@@ -178,8 +178,8 @@ exports.m = mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-config-changes-declaration-dir.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-config-changes-declaration-dir.js
index 75e23dfa0af..829dbe1718f 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-config-changes-declaration-dir.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-config-changes-declaration-dir.js
@@ -185,8 +185,8 @@ exports.multiply = multiply;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
@@ -370,8 +370,8 @@ sourceFile:index.ts
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
@@ -436,8 +436,8 @@ exports.m = mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-specifies-tsBuildInfoFile.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-specifies-tsBuildInfoFile.js
index f419af6508a..5dab84c64ac 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-specifies-tsBuildInfoFile.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-logic-specifies-tsBuildInfoFile.js
@@ -185,8 +185,8 @@ exports.multiply = multiply;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
@@ -370,8 +370,8 @@ sourceFile:index.ts
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
@@ -453,8 +453,8 @@ exports.m = mod;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../core/index.ts": {
         "version": "-13851440507",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-module-option-changes.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-module-option-changes.js
index 54e0f764dac..abc90d83d09 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-module-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-module-option-changes.js
@@ -27,8 +27,8 @@ exports.multiply = multiply;
   "program": {
     "fileInfos": {
       "../../lib/lib.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "./anothermodule.ts": {
         "version": "-2676574883",
diff --git a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-target-option-changes.js b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-target-option-changes.js
index c31d39c0647..74efec1e633 100644
--- a/tests/baselines/reference/tsbuild/sample1/initial-Build/when-target-option-changes.js
+++ b/tests/baselines/reference/tsbuild/sample1/initial-Build/when-target-option-changes.js
@@ -13,7 +13,7 @@ interface Number { toExponential: any; }
 interface Object {}
 interface RegExp {}
 interface String { charAt: any; }
-interface Array<T> {}
+interface Array<T> { length: number; [n: number]: T; }
 interface ReadonlyArray<T> {}
 declare const console: { log(msg: any): void; };
 
@@ -46,8 +46,8 @@ export function multiply(a, b) { return a * b; }
   "program": {
     "fileInfos": {
       "../../lib/lib.esnext.d.ts": {
-        "version": "-15964756381",
-        "signature": "-15964756381"
+        "version": "3858781397",
+        "signature": "3858781397"
       },
       "../../lib/lib.esnext.full.d.ts": {
         "version": "8926001564",
diff --git a/tests/projects/demo/animals/animal.ts b/tests/projects/demo/animals/animal.ts
new file mode 100644
index 00000000000..30727d46489
--- /dev/null
+++ b/tests/projects/demo/animals/animal.ts
@@ -0,0 +1,4 @@
+export type Size = "small" | "medium" | "large";
+export default interface Animal {
+    size: Size;
+}
diff --git a/tests/projects/demo/animals/dog.ts b/tests/projects/demo/animals/dog.ts
new file mode 100644
index 00000000000..3e51978e7f0
--- /dev/null
+++ b/tests/projects/demo/animals/dog.ts
@@ -0,0 +1,18 @@
+import Animal from '.';
+import { makeRandomName } from '../core/utilities';
+
+export interface Dog extends Animal {
+    woof(): void;
+    name: string;
+}
+
+export function createDog(): Dog {
+    return ({
+        size: "medium",
+        woof: function(this: Dog) {
+            console.log(`${this.name} says "Woof"!`);
+        },
+        name: makeRandomName()
+    });
+}
+
diff --git a/tests/projects/demo/animals/index.ts b/tests/projects/demo/animals/index.ts
new file mode 100644
index 00000000000..9d4734f2eb7
--- /dev/null
+++ b/tests/projects/demo/animals/index.ts
@@ -0,0 +1,5 @@
+import Animal from './animal';
+
+export default Animal;
+import { createDog, Dog } from './dog';
+export { createDog, Dog };
diff --git a/tests/projects/demo/animals/tsconfig.json b/tests/projects/demo/animals/tsconfig.json
new file mode 100644
index 00000000000..f6b2cc49e44
--- /dev/null
+++ b/tests/projects/demo/animals/tsconfig.json
@@ -0,0 +1,10 @@
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "outDir": "../lib/animals",
+    "rootDir": ".",
+  },
+  "references": [
+    { "path": "../core" }
+  ]
+}
diff --git a/tests/projects/demo/core/tsconfig.json b/tests/projects/demo/core/tsconfig.json
new file mode 100644
index 00000000000..9b381b9a5cf
--- /dev/null
+++ b/tests/projects/demo/core/tsconfig.json
@@ -0,0 +1,7 @@
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "outDir": "../lib/core",
+    "rootDir": "."
+  }
+}
\ No newline at end of file
diff --git a/tests/projects/demo/core/utilities.ts b/tests/projects/demo/core/utilities.ts
new file mode 100644
index 00000000000..0988afaf4c3
--- /dev/null
+++ b/tests/projects/demo/core/utilities.ts
@@ -0,0 +1,10 @@
+
+export function makeRandomName() {
+    return "Bob!?! ";
+}
+
+export function lastElementOf<T>(arr: T[]): T | undefined {
+    if (arr.length === 0) return undefined;
+    return arr[arr.length - 1];
+}
+
diff --git a/tests/projects/demo/tsconfig-base.json b/tests/projects/demo/tsconfig-base.json
new file mode 100644
index 00000000000..e5d5ba5c7ce
--- /dev/null
+++ b/tests/projects/demo/tsconfig-base.json
@@ -0,0 +1,13 @@
+{
+    "compilerOptions": {
+        "declaration": true,
+        "target": "es5",
+        "module": "commonjs",
+        "strict": true,
+        "noUnusedLocals": true,
+        "noUnusedParameters": true,
+        "noImplicitReturns": true,
+        "noFallthroughCasesInSwitch": true,
+        "composite": true
+    }
+}
\ No newline at end of file
diff --git a/tests/projects/demo/tsconfig.json b/tests/projects/demo/tsconfig.json
new file mode 100644
index 00000000000..a140d4ef8e2
--- /dev/null
+++ b/tests/projects/demo/tsconfig.json
@@ -0,0 +1,14 @@
+{
+  "files": [],
+  "references": [
+    {
+      "path": "./core"
+    },
+    {
+      "path": "./animals"
+    },
+    {
+      "path": "./zoo"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/tests/projects/demo/zoo/tsconfig.json b/tests/projects/demo/zoo/tsconfig.json
new file mode 100644
index 00000000000..318c0dc06b6
--- /dev/null
+++ b/tests/projects/demo/zoo/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "extends": "../tsconfig-base.json",
+  "compilerOptions": {
+    "outDir": "../lib/zoo",
+    "rootDir": "."
+  },
+  "references": [
+    {
+      "path": "../animals"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/tests/projects/demo/zoo/zoo.ts b/tests/projects/demo/zoo/zoo.ts
new file mode 100644
index 00000000000..a00ad8a79e4
--- /dev/null
+++ b/tests/projects/demo/zoo/zoo.ts
@@ -0,0 +1,9 @@
+// import Animal from '../animals/index';
+import { Dog, createDog } from '../animals/index';
+
+export function createZoo(): Array<Dog> {
+    return [
+        createDog()
+    ];
+}
+