diff --git a/src/__tests__/correlation-single-implementation-guard.test.ts b/src/__tests__/correlation-single-implementation-guard.test.ts
index f9697ab84..708118b23 100644
--- a/src/__tests__/correlation-single-implementation-guard.test.ts
+++ b/src/__tests__/correlation-single-implementation-guard.test.ts
@@ -21,7 +21,7 @@ import { readFileSync } from "node:fs";
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
 
-import { walkSourceFiles } from "./helpers/source-files";
+import { stripComments, walkSourceFiles } from "./helpers/source-files";
 
 const SRC = join(process.cwd(), "src");
 
@@ -34,10 +34,6 @@ const PEARSON_DEFINITION =
   /(?:function\s+|const\s+)\w*(?:pearson|correlationCoefficient)\w*\s*(?:=|\()/i;
 const DELETED = /(?<![A-Za-z])pearsonCorrelation\b/;
 
-function stripComments(text: string): string {
-  return text.replace(/\/\*[\s\S]*?\*\//g, "").replace(/^\s*\/\/.*$/gm, "");
-}
-
 function sourceFiles(): string[] {
   return walkSourceFiles(SRC, { floor: 3000 }).filter(
     (p) =>
diff --git a/src/__tests__/dose-ledger-single-source-guard.test.ts b/src/__tests__/dose-ledger-single-source-guard.test.ts
index aff5974b4..071e24536 100644
--- a/src/__tests__/dose-ledger-single-source-guard.test.ts
+++ b/src/__tests__/dose-ledger-single-source-guard.test.ts
@@ -16,7 +16,7 @@ import { readFileSync } from "node:fs";
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
 
-import { walkSourceFiles } from "./helpers/source-files";
+import { stripComments, walkSourceFiles } from "./helpers/source-files";
 
 const SRC = join(process.cwd(), "src");
 
@@ -31,10 +31,6 @@ const CALLERS: Record<string, string> = {
 
 const CALL = /\breconstructDoseHistory\s*\(/;
 
-function stripComments(text: string): string {
-  return text.replace(/\/\*[\s\S]*?\*\//g, "").replace(/^\s*\/\/.*$/gm, "");
-}
-
 describe("one compliance ledger", () => {
   it("the dose rows are built only where this file says", () => {
     const callers = walkSourceFiles(SRC, { floor: 3000 })
diff --git a/src/__tests__/insights-cached-text-access-guard.test.ts b/src/__tests__/insights-cached-text-access-guard.test.ts
index e9121158b..f5cff3900 100644
--- a/src/__tests__/insights-cached-text-access-guard.test.ts
+++ b/src/__tests__/insights-cached-text-access-guard.test.ts
@@ -19,7 +19,7 @@ import { join } from "node:path";
 
 import { describe, expect, it } from "vitest";
 
-import { walkSourceFiles } from "./helpers/source-files";
+import { stripComments, walkSourceFiles } from "./helpers/source-files";
 
 const SRC = join(process.cwd(), "src");
 
@@ -37,24 +37,15 @@ const ALLOWED: Readonly<Record<string, string>> = {
     "fills that input field from openInsightsCachedText",
 };
 
-/** The legacy name, not its sealed sibling, outside comment lines. */
+/** The legacy name, not its sealed sibling, outside comments. */
 const LEGACY_NAME = /\binsightsCachedText\b(?!Encrypted)/;
 
-function codeLines(source: string): string[] {
-  return source.split("\n").filter((line) => {
-    const t = line.trim();
-    return !(t.startsWith("*") || t.startsWith("//") || t.startsWith("/*"));
-  });
-}
-
 function filesSpellingTheLegacyName(): string[] {
   return walkSourceFiles(SRC, { floor: 2000 })
     .filter((f) => !f.startsWith("generated/"))
     .filter((f) => !f.includes("__tests__/") && !/\.test\.tsx?$/.test(f))
     .filter((f) =>
-      codeLines(readFileSync(join(SRC, f), "utf8")).some((l) =>
-        LEGACY_NAME.test(l),
-      ),
+      LEGACY_NAME.test(stripComments(readFileSync(join(SRC, f), "utf8"))),
     );
 }
 
diff --git a/src/__tests__/latest-per-type-read-guard.test.ts b/src/__tests__/latest-per-type-read-guard.test.ts
index a0e7eb796..21f38c950 100644
--- a/src/__tests__/latest-per-type-read-guard.test.ts
+++ b/src/__tests__/latest-per-type-read-guard.test.ts
@@ -21,17 +21,15 @@ import { readFileSync } from "node:fs";
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
 
-import { walkSourceFiles } from "./helpers/source-files";
+import { stripComments, walkSourceFiles } from "./helpers/source-files";
+
+/** The shared comment strip, plus SQL line comments inside template strings. */
+function stripCode(text: string): string {
+  return stripComments(text).replace(/^\s*--.*$/gm, "");
+}
 
 const SRC = join(process.cwd(), "src");
 
-function stripComments(text: string): string {
-  return text
-    .replace(/\/\*[\s\S]*?\*\//g, "")
-    .replace(/^\s*\/\/.*$/gm, "")
-    .replace(/^\s*--.*$/gm, "");
-}
-
 /** `DISTINCT ON (type)` or `DISTINCT ON (m."type")`, the type alone. */
 const LATEST_PER_TYPE = /DISTINCT\s+ON\s*\(\s*(?:\w+\s*\.\s*)?"?type"?\s*\)/i;
 
@@ -64,18 +62,14 @@ describe("latest-per-type reads", () => {
 
   it("no production read keeps one row per type with DISTINCT ON", () => {
     const offenders = productionFiles().filter((file) =>
-      LATEST_PER_TYPE.test(
-        stripComments(readFileSync(join(SRC, file), "utf8")),
-      ),
+      LATEST_PER_TYPE.test(stripCode(readFileSync(join(SRC, file), "utf8"))),
     );
     expect(offenders).toEqual([]);
   });
 
   it("the summaries slice is built only behind its cache cell", () => {
     const callers = productionFiles().filter((file) =>
-      SLICE_BUILDER_CALL.test(
-        stripComments(readFileSync(join(SRC, file), "utf8")),
-      ),
+      SLICE_BUILDER_CALL.test(stripCode(readFileSync(join(SRC, file), "utf8"))),
     );
     expect(callers).toEqual(["lib/analytics/summaries-slice.ts"]);
   });
diff --git a/src/__tests__/naive-timestamp-zone-shift-guard.test.ts b/src/__tests__/naive-timestamp-zone-shift-guard.test.ts
index cfb111b5a..1ae978874 100644
--- a/src/__tests__/naive-timestamp-zone-shift-guard.test.ts
+++ b/src/__tests__/naive-timestamp-zone-shift-guard.test.ts
@@ -21,7 +21,12 @@ import { readFileSync } from "node:fs";
 import { join } from "node:path";
 import { describe, expect, it } from "vitest";
 
-import { walkSourceFiles } from "./helpers/source-files";
+import { stripComments, walkSourceFiles } from "./helpers/source-files";
+
+/** The shared comment strip, plus SQL line comments inside template strings. */
+function stripCode(text: string): string {
+  return stripComments(text).replace(/^\s*--.*$/gm, "");
+}
 
 const SRC = join(process.cwd(), "src");
 
@@ -31,13 +36,6 @@ const SINGLE_SHIFT =
 const DOUBLE_SHIFT =
   /AT\s+TIME\s+ZONE\s+'UTC'\s*\)?\s*AT\s+TIME\s+ZONE\s+(?:\$\{|\$\d)/i;
 
-function stripComments(text: string): string {
-  return text
-    .replace(/\/\*[\s\S]*?\*\//g, "")
-    .replace(/^\s*\/\/.*$/gm, "")
-    .replace(/^\s*--.*$/gm, "");
-}
-
 describe("naive timestamp zone shifts", () => {
   it("the matcher fires on the single shift and spares the double one", () => {
     expect(
@@ -62,7 +60,7 @@ describe("naive timestamp zone shifts", () => {
         !/\.test\.tsx?$/.test(file),
     );
     const code = (file: string) =>
-      stripComments(readFileSync(join(SRC, file), "utf8"));
+      stripCode(readFileSync(join(SRC, file), "utf8"));
     // The reads that shift correctly, so a sweep that reads nothing fails.
     const doubleShifts = files.filter((file) => DOUBLE_SHIFT.test(code(file)));
     expect(doubleShifts.length).toBeGreaterThanOrEqual(5);