Switch size-limit to JSON-based results for better reliability

.github/actions/size-limit/package.json

@@ -7,11 +7,13 @@
 		"typecheck": "tsc --noEmit"
 	},
 	"devDependencies": {
-		"@types/bun": "latest"
+		"@types/bun": "^1.3.5",
+		"@types/node": "^25.0.6"
 	},
 	"packageManager": "bun@1.2.22",
 	"dependencies": {
 		"arkregex": "0.0.5",
+		"glob": "^13.0.0",
 		"typescript": "5.9.3"
 	}
 }

.github/actions/size-limit/src/package/names.ts

@@ -23,9 +23,7 @@ export const getFilenameFromConfig = (packageName: string): string | null => {
 						packagePath = `packages/${folder}`;
 						break;
 					}
-				} catch {
-					continue;
-				}
+				} catch {}
 			}
 		}
 

.github/actions/size-limit/src/size-limit/run.ts

@@ -1,6 +1,10 @@
 import { spawn } from "bun";
 import type { SizeLimitResult } from "../types.ts";
-import { parseSizeLimitOutput, getPackageNames } from "../utils/parser.ts";
+import {
+	getPackageNames,
+	parseJsonFiles,
+	parseSizeLimitOutput,
+} from "../utils/parser.ts";
 
 /**
  * Runs size-limit for the current branch and returns parsed results.
@@ -41,8 +45,17 @@ export const runSizeLimit = async (
 		const exitCode = await proc.exited;
 		const rawOutput = stdout + stderr;
 
-		// Parse results using the captured target packages
-		const results = parseSizeLimitOutput(rawOutput, targetPackages);
+		// 1. Try to parse JSON files first
+		let results = await parseJsonFiles();
+
+		// 2. Fallback to stdout parsing if no JSON results were found
+		// This happens when checking out main where size-limit --json hasn't been added yet
+		if (results.length === 0) {
+			process.stdout.write(
+				"ℹ️ No JSON results found. Falling back to stdout parsing...\n",
+			);
+			results = parseSizeLimitOutput(rawOutput, targetPackages);
+		}
 
 		return {
 			results,

.github/actions/size-limit/src/utils/parser.ts

@@ -1,33 +1,86 @@
 import * as fs from "node:fs";
 import * as path from "node:path";
+import { regex } from "arkregex";
+import { glob } from "glob";
 import type { SizeLimitResult, SizeLimitState } from "../types.ts";
+import { formatBytes } from "./size.ts";
+
+/**
+ * Reads and parses .size-limit.json files from all packages.
+ */
+export async function parseJsonFiles(): Promise<SizeLimitResult[]> {
+	const results: SizeLimitResult[] = [];
+	const files = glob.sync("packages/**/.size-limit.json", {
+		ignore: ["**/node_modules/**", "**/.turbo/**"],
+	});
+
+	for (const file of files) {
+		try {
+			const content = fs.readFileSync(file, "utf-8");
+			const data = JSON.parse(content);
+
+			const dir = path.dirname(file);
+			let pkgName = path.basename(dir);
+			try {
+				const pkgJsonPath = path.join(dir, "package.json");
+				const pkgJson = JSON.parse(fs.readFileSync(pkgJsonPath, "utf-8"));
+				pkgName = pkgJson.name || pkgName;
+			} catch {
+				// Fallback to folder name
+			}
+
+			if (Array.isArray(data)) {
+				for (const item of data) {
+					// size-limit --json uses 'size' and 'sizeLimit' as numbers
+					const rawSize = item.size;
+					const rawLimit = item.sizeLimit ?? item.limit;
+
+					const size =
+						typeof rawSize === "number"
+							? formatBytes(rawSize)
+							: rawSize || "0 B";
+					const limit =
+						typeof rawLimit === "number"
+							? formatBytes(rawLimit)
+							: rawLimit || "—";
+
+					results.push({
+						package: pkgName,
+						file: item.name || item.path || "index.js",
+						size,
+						limit,
+						status: item.passed !== false ? "✅" : "❌",
+					});
+				}
+			}
+		} catch (error) {
+			process.stdout.write(`DEBUG: Failed to parse ${file}: ${error}\n`);
+		}
+	}
+
+	return results;
+}
 
 /**
  * Normalizes package names from Turbo/GHA output.
  */
 export const normalizePackageName = (name: string): string => {
-	// Remove GHA timestamps if they exist
 	let normalized = name.replace(
 		/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d+Z\s*/,
 		"",
 	);
-
-	// Remove Turbo status characters from the start
 	normalized = normalized.replace(/^[○●•✔✖ℹ⚠»>\s]+/, "");
 
-	// Remove Turbo prefixes like "packages/arkenv (arkenv)" -> "arkenv"
 	const parenMatch = normalized.match(/\(([^)]+)\)$/);
 	if (parenMatch) {
 		normalized = parenMatch[1] ?? normalized;
 	}
 
-	// Handle "package@version task"
 	const taskMatch = normalized.match(/^([^@\s]+)@\d+\.\d+\.\d+\s+([^:]+)/);
 	if (taskMatch) {
 		normalized = taskMatch[1] ?? normalized;
 	}
 
-	// Handle "package:size" or "package#size"
 	if (normalized.includes(":") || normalized.includes("#")) {
 		const parts = normalized.split(/[:#]/);
 		normalized = (parts[0] ?? normalized).trim();
@@ -37,7 +90,7 @@ export const normalizePackageName = (name: string): string => {
 };
 
 /**
- * Gets all package names in the monorepo to help with attribution.
+ * Gets all package names in the monorepo.
  */
 export function getPackageNames(): string[] {
 	const results: string[] = [];
@@ -52,34 +105,17 @@ export function getPackageNames(): string[] {
 				if (fs.existsSync(pkgPath)) {
 					const pkg = JSON.parse(fs.readFileSync(pkgPath, "utf-8"));
 					if (pkg.name) results.push(pkg.name);
-				} else {
-					// Handle scoped packages in subdirectories
-					const subDir = path.join(packagesDir, dirent.name);
-					const subDirents = fs.readdirSync(subDir, { withFileTypes: true });
-					for (const subDirent of subDirents) {
-						if (subDirent.isDirectory()) {
-							const subPkgPath = path.join(
-								subDir,
-								subDirent.name,
-								"package.json",
-							);
-							if (fs.existsSync(subPkgPath)) {
-								const subPkg = JSON.parse(fs.readFileSync(subPkgPath, "utf-8"));
-								if (subPkg.name) results.push(subPkg.name);
-							}
-						}
-					}
 				}
 			}
 		}
-	} catch (error) {
+	} catch {
 		// Silent fail
 	}
 	return results;
 }
 
 /**
- * Parses the raw output of size-limit.
+ * Parses raw output string for fallback support.
  */
 export function parseSizeLimitOutput(
 	output: string,
@@ -157,8 +193,8 @@ export function parseSizeLimitOutput(
 		}
 	};
 
-	const ansiRegex = new RegExp(
-		"[\\u001b\\u009b][[()#;?]*(?:[0-9]{1,4}(?:;[0-9]{0,4})*)?[0-9A-ORZcf-nqry=><]",
+	const ansiRegex = regex(
+		"[\u001b\u009b][[()#;?]*(?:[0-9]{1,4}(?:;[0-9]{0,4})*)?[0-9A-ORZcf-nqry=><]",
 		"g",
 	);
 
@@ -171,7 +207,6 @@ export function parseSizeLimitOutput(
 		const strippedLine = lineNoTimestamp.replace(/^[\s|>○●•✔✖ℹ⚠]+/, "").trim();
 		if (!strippedLine) continue;
 
-		// 1. Group Detection (Context is "sticky")
 		if (strippedLine.includes("##[group]")) {
 			const groupContent = strippedLine.split("##[group]")[1]?.trim();
 			if (groupContent) {
@@ -188,7 +223,6 @@ export function parseSizeLimitOutput(
 			}
 		}
 
-		// 2. Header Detection
 		const headerMatch = strippedLine.match(
 			/([@a-z0-9/._-]+)\s*[:#]\s*size(?:\s*[:#]\s*(.*))?/i,
 		);
@@ -209,7 +243,6 @@ export function parseSizeLimitOutput(
 			continue;
 		}
 
-		// 3. Attribution fallback for replayed logs
 		const lineAttributed = (() => {
 			for (const pkg of relevantPackages) {
 				const unscoped = pkg.startsWith("@") ? (pkg.split("/")[1] ?? pkg) : pkg;
@@ -232,7 +265,6 @@ export function parseSizeLimitOutput(
 		})();
 		if (lineAttributed) continue;
 
-		// 4. Final fallback for guessing context
 		if (!lastPackage && strippedLine.match(/size:|size\s*limit/i)) {
 			for (const pkg of relevantPackages) {
 				const unscoped = pkg.startsWith("@") ? (pkg.split("/")[1] ?? pkg) : pkg;
@@ -246,7 +278,6 @@ export function parseSizeLimitOutput(
 			}
 		}
 
-		// 5. Apply context
 		if (lastPackage) {
 			parseMessageLine(lastPackage, strippedLine);
 		}

.github/actions/size-limit/src/utils/size.ts

@@ -60,3 +60,15 @@ export const calculateDiff = (
 	const sign = diff > 0 ? "+" : "";
 	return `${sign}${diff.toFixed(1)}%`;
 };
+
+// Format bytes to human readable string
+export const formatBytes = (bytes: number): string => {
+	if (bytes === 0) return "0 B";
+	const k = 1024;
+	const sizes = ["B", "kB", "MB", "GB", "TB"];
+	const i = Math.min(
+		Math.floor(Math.log(bytes) / Math.log(k)),
+		sizes.length - 1,
+	);
+	return `${Number.parseFloat((bytes / k ** i).toFixed(2))} ${sizes[i]}`;
+};

.gitignore

@@ -42,6 +42,7 @@ pnpm-debug.log*
 coverage/
 
 # size-limit
+.size-limit.json
 esbuild-why*.html
 
 # arktype clone

packages/arkenv/package.json

@@ -13,7 +13,7 @@
 	},
 	"scripts": {
 		"build": "tsdown",
-		"size": "size-limit",
+		"size": "size-limit --json > .size-limit.json",
 		"test:once": "pnpm test",
 		"typecheck": "tsc --noEmit",
 		"clean": "rimraf dist node_modules",

packages/bun-plugin/package.json

@@ -56,7 +56,7 @@
 		"test": "vitest",
 		"fix": "pnpm -w run fix",
 		"changeset": "pnpm -w run changeset",
-		"size": "size-limit"
+		"size": "size-limit --json > .size-limit.json"
 	},
 	"type": "module",
 	"types": "./dist/index.d.ts",

packages/vite-plugin/package.json

@@ -56,7 +56,7 @@
 		"test": "vitest",
 		"fix": "pnpm -w run fix",
 		"changeset": "pnpm -w run changeset",
-		"size": "size-limit"
+		"size": "size-limit --json > .size-limit.json"
 	},
 	"type": "module",
 	"types": "./dist/index.d.ts",

turbo.json

@@ -63,6 +63,10 @@
 			"cache": false,
 			"persistent": true
 		},
-		"test:e2e:update": {}
+		"test:e2e:update": {},
+		"size": {
+			"dependsOn": ["^build"],
+			"outputs": [".size-limit.json"]
+		}
 	}
 }