fix: highlight escaped JSON strings correctly

.changeset/json-string-escapes.md

@@ -0,0 +1,8 @@
+---
+"cf": patch
+---
+
+Fix JSON string highlighting for escaped quotation marks
+
+Keep the complete string value highlighted when JSON contains escaped quotes
+or backslashes. Non-interactive output remains plain, parseable JSON.

packages/cli/src/__tests__/lib/output.test.ts

@@ -1,3 +1,4 @@
+import { stripVTControlCharacters } from "node:util";
 import chalk from "chalk";
 import {
 	afterEach,
@@ -8,6 +9,7 @@ import {
 	vi,
 } from "vite-plus/test";
 import { formatOutput } from "../../lib/output.js";
+import { theme } from "../../lib/ui/theme.js";
 import { Page } from "../../sdk/sdk/core/pagination/Page.js";
 
 const ciInfo = vi.hoisted(() => ({ isCI: false }));
@@ -163,6 +165,78 @@ describe("formatOutput", () => {
 		expect(loggedJson()).toEqual(["a", "b"]);
 	});
 
+	describe("JSON string highlighting", () => {
+		const cases = [
+			{ name: "plain strings", value: "cat.com" },
+			{ name: "empty strings", value: "" },
+			{
+				name: "escaped quotation marks",
+				serializedValue: String.raw`"\"cat.com\""`,
+				value: '"cat.com"',
+			},
+			{ name: "embedded quotation marks", value: 'say "hello"' },
+			{
+				name: "escaped quotation marks followed by a colon",
+				serializedValue: String.raw`"\"key\": text"`,
+				value: '"key": text',
+			},
+			{ name: "backslashes before quotation marks", value: '\\"cat.com\\"' },
+			{
+				name: "Windows paths with trailing backslashes",
+				value: "C:\\Users\\cat\\",
+			},
+			{ name: "consecutive backslashes", value: "\\\\server\\share\\" },
+			{ name: "other JSON escapes", value: "line\n\t\r\b\f\u0000/end" },
+		];
+		let originalChalkLevel: typeof chalk.level;
+
+		beforeEach(() => {
+			originalChalkLevel = chalk.level;
+			chalk.level = 3;
+			vi.stubEnv("FORCE_COLOR", "1");
+			vi.stubEnv("NO_COLOR", undefined);
+			setStdinTTY(true);
+			setStdoutTTY(true);
+		});
+
+		afterEach(() => {
+			chalk.level = originalChalkLevel;
+		});
+
+		it.each(cases)(
+			"highlights complete $name",
+			({ serializedValue, value }) => {
+				const data = { value };
+				formatOutput(data);
+
+				const output = String(logSpy.mock.calls[0]?.[0]);
+				expect(output).toBe(
+					`{\n  ${theme.jsonKey('"value"')}: ${theme.jsonString(serializedValue ?? JSON.stringify(value))}\n}`
+				);
+				expect(JSON.parse(stripVTControlCharacters(output))).toEqual(data);
+			}
+		);
+
+		it.each(["non-TTY stdout", "NO_COLOR"])(
+			"preserves plain, parseable JSON with %s",
+			(mode) => {
+				if (mode === "NO_COLOR") {
+					vi.stubEnv("NO_COLOR", "1");
+				} else {
+					setStdoutTTY(false);
+				}
+
+				const data = cases.map(({ value }) => ({ value }));
+				formatOutput(data);
+
+				expect(logSpy).toHaveBeenCalledExactlyOnceWith(
+					JSON.stringify(data, null, 2)
+				);
+				expect(loggedJson()).toEqual(data);
+			}
+		);
+	});
+
 	it("prints the payload from a Fern page response", () => {
 		formatOutput({
 			result: [{ id: "one" }, { id: "two" }],

packages/cli/src/lib/output.ts

@@ -78,9 +78,16 @@ function formatJson(data: unknown): string {
 	}
 
 	return json
-		.replace(/"([^"]+)":/g, (_match, key) => `${theme.jsonKey(`"${key}"`)}:`)
 		.replace(
-			/: "([^"]*)"/g,
+			// Match a quoted key followed by a colon, consuming escapes as pairs
+			// so escaped quotes inside a value cannot be mistaken for key delimiters.
+			/"((?:[^"\\]|\\.)*)":/g,
+			(_match, key) => `${theme.jsonKey(`"${key}"`)}:`
+		)
+		.replace(
+			// Match a quoted value after a colon, consuming escapes as pairs
+			// so only an unescaped quote can end the string.
+			/: "((?:[^"\\]|\\.)*)"/g,
 			(_match, value) => `: ${theme.jsonString(`"${value}"`)}`
 		)
 		.replace(/: (-?\d+\.?\d*)/g, (_match, num) => `: ${theme.jsonNumber(num)}`)