diff --git a/src/application/javascript/JavaScriptSemanticGraphBuilder.test.ts b/src/application/javascript/JavaScriptSemanticGraphBuilder.test.ts
index 54ecec21ed..43d63a7d05 100644
--- a/src/application/javascript/JavaScriptSemanticGraphBuilder.test.ts
+++ b/src/application/javascript/JavaScriptSemanticGraphBuilder.test.ts
@@ -1,3 +1,4 @@
+import { primitiveByteExpansionSource } from "../../../tests/fixtures/javascriptPrimitiveExpansion.js";
 import * as t from "@babel/types";
 import { expect, it } from "vitest";
 
@@ -111,15 +112,7 @@ it("preserves primitive candidate budget unknowns in semantic graph coverage", (
 });
 
 it("preserves derived string-byte limit reasons in semantic graph unknowns", () => {
-  const declarations = ['const value0 = "x";'];
-  for (let index = 1; index <= 30; index += 1) {
-    const previous = `value${String(index - 1)}`;
-    declarations.push(
-      `const value${String(index)} = ${previous} + ${previous};`,
-    );
-  }
-  declarations.push("const answer = value30;");
-  const source = declarations.join("\n");
+  const source = primitiveByteExpansionSource();
   const ir = analyzeJavaScriptSemantics(source);
   const graph = graphFor(source, ir);
 
diff --git a/tests/boundary/filesystem/javascriptIntegrityPolicy.test.ts b/tests/boundary/filesystem/javascriptIntegrityPolicy.test.ts
index 7291d888e2..9fd482ec27 100644
--- a/tests/boundary/filesystem/javascriptIntegrityPolicy.test.ts
+++ b/tests/boundary/filesystem/javascriptIntegrityPolicy.test.ts
@@ -1,3 +1,7 @@
+import {
+  primitiveCandidateExpansionSource,
+  primitiveByteExpansionSource,
+} from "../../fixtures/javascriptPrimitiveExpansion.js";
 import { createHash } from "node:crypto";
 import { mkdir, readFile, writeFile } from "node:fs/promises";
 import { join } from "node:path";
@@ -102,21 +106,9 @@ it("keeps a contradicted nested ASAR opaque during JavaScript reconstruction", a
 });
 
 it("retains semantic resource limits alongside recorded integrity contradictions", async () => {
-  const expression = Array.from(
-    { length: 20 },
-    () => '(true ? "a" : "b")',
-  ).join(" + ");
-  const declarations = ['const value0 = "x";'];
-  for (let index = 1; index <= 30; index += 1) {
-    const previous = `value${String(index - 1)}`;
-    declarations.push(
-      `const value${String(index)} = ${previous} + ${previous};`,
-    );
-  }
-  declarations.push("const answer = value30;");
   const { archive } = await createStrippedAsarAddon([
-    { path: "app.js", contents: `const answer = { nested: ${expression} };` },
-    { path: "growth.js", contents: declarations.join("\n") },
+    { path: "app.js", contents: primitiveCandidateExpansionSource() },
+    { path: "growth.js", contents: primitiveByteExpansionSource() },
   ]);
   const analyzed = await analyzeJavaScriptApplication({
     input_path: archive,
diff --git a/tests/composition/javascript-applications/javascriptArtifactReconstruction.test.ts b/tests/composition/javascript-applications/javascriptArtifactReconstruction.test.ts
index 2775b0cb84..4bbc2eb367 100644
--- a/tests/composition/javascript-applications/javascriptArtifactReconstruction.test.ts
+++ b/tests/composition/javascript-applications/javascriptArtifactReconstruction.test.ts
@@ -1,3 +1,7 @@
+import {
+  primitiveCandidateExpansionSource,
+  primitiveByteExpansionSource,
+} from "../../fixtures/javascriptPrimitiveExpansion.js";
 import { createHash } from "node:crypto";
 import { mkdir, rm, writeFile } from "node:fs/promises";
 import { join } from "node:path";
@@ -102,23 +106,8 @@ it("preserves graph commitments and export shapes when consuming file-local IR",
 
 it("reports semantic value resource limits in application graph coverage", async () => {
   const root = await createTestTempDirectory("rea-javascript-semantic-limit-");
-  const expression = Array.from(
-    { length: 20 },
-    () => '(true ? "a" : "b")',
-  ).join(" + ");
-  await writeFile(
-    join(root, "app.js"),
-    `const answer = { nested: ${expression} };`,
-  );
-  const declarations = ['const value0 = "x";'];
-  for (let index = 1; index <= 30; index += 1) {
-    const previous = `value${String(index - 1)}`;
-    declarations.push(
-      `const value${String(index)} = ${previous} + ${previous};`,
-    );
-  }
-  declarations.push("const answer = value30;");
-  await writeFile(join(root, "growth.js"), declarations.join("\n"));
+  await writeFile(join(root, "app.js"), primitiveCandidateExpansionSource());
+  await writeFile(join(root, "growth.js"), primitiveByteExpansionSource());
   const snapshot = await scanCanonicalArtifactInventory(root, {});
   const reader = createJavaScriptArtifactReader(root, "directory");
   try {
diff --git a/tests/fixtures/javascriptPrimitiveExpansion.ts b/tests/fixtures/javascriptPrimitiveExpansion.ts
new file mode 100644
index 0000000000..1189dc9025
--- /dev/null
+++ b/tests/fixtures/javascriptPrimitiveExpansion.ts
@@ -0,0 +1,21 @@
+/** Source whose concatenated alternatives exceed primitive candidate storage. */
+export const primitiveCandidateExpansionSource = (): string => {
+  const expression = Array.from(
+    { length: 20 },
+    () => '(true ? "a" : "b")',
+  ).join(" + ");
+  return `const answer = { nested: ${expression} };`;
+};
+
+/** Source whose repeated doubling exceeds derived primitive string storage. */
+export const primitiveByteExpansionSource = (): string => {
+  const declarations = ['const value0 = "x";'];
+  for (let index = 1; index <= 30; index += 1) {
+    const previous = `value${String(index - 1)}`;
+    declarations.push(
+      `const value${String(index)} = ${previous} + ${previous};`,
+    );
+  }
+  declarations.push("const answer = value30;");
+  return declarations.join("\n");
+};