Allow formatting unmatched patterns

.changeset/cold-steaks-trade.md

@@ -0,0 +1,5 @@
+---
+"@changesets/format": patch
+---
+
+Allow `format()` to pass even if the patterns didn't match any files

README.md

@@ -25,7 +25,7 @@ Options can be passed to the first parameter:
 
 ### `format()`
 
-Format the given patterns with a specified or auto-detected formatter. It returns `true` if a formatter is found and the formatting process passes, otherwise returns `false`.
+Format the given patterns with a specified or auto-detected formatter. It returns `true` if a formatter is found and the formatting process passes (even if the patterns didn't match any files), otherwise returns `false`.
 
 <!-- NOTE: Docs should match src/format.ts -->
 

src/format.ts

@@ -29,7 +29,8 @@ export interface FormatOptions {
 
 /**
  * Format the given patterns with a specified or auto-detected formatter. It returns `true` if a
- * formatter is found and the formatting process passes, otherwise returns `false`.
+ * formatter is found and the formatting process passes (even if the patterns didn't match any
+ * files), otherwise returns `false`.
  */
 export async function format(patterns: string[], options: FormatOptions = {}): Promise<boolean> {
   const formatterName =

src/formatters.ts

@@ -58,7 +58,11 @@ const prettier: Formatter = {
   ],
   async format(files, ctx) {
     const pm = await ctx.getPackageManager();
-    await packageManagerExecute(pm, ["prettier", "--write", ...files], ctx.cwd);
+    await packageManagerExecute(
+      pm,
+      ["prettier", "--write", "--no-error-on-unmatched-pattern", ...files],
+      ctx.cwd,
+    );
   },
 };
 
@@ -69,7 +73,11 @@ const biome: Formatter = {
   configFiles: ["biome.json", "biome.jsonc", ".biome.json", ".biome.jsonc"],
   async format(files, ctx) {
     const pm = await ctx.getPackageManager();
-    await packageManagerExecute(pm, ["@biomejs/biome", "format", "--write", ...files], ctx.cwd);
+    await packageManagerExecute(
+      pm,
+      ["@biomejs/biome", "format", "--write", "--no-errors-on-unmatched", ...files],
+      ctx.cwd,
+    );
   },
 };
 
@@ -80,7 +88,11 @@ const oxfmt: Formatter = {
   configFiles: [".oxfmtrc.json", ".oxfmtrc.jsonc", "oxfmt.config.ts", "oxfmt.config.mts"],
   async format(files, ctx) {
     const pm = await ctx.getPackageManager();
-    await packageManagerExecute(pm, ["oxfmt", "--write", ...files], ctx.cwd);
+    await packageManagerExecute(
+      pm,
+      ["oxfmt", "--write", "--no-error-on-unmatched-pattern", ...files],
+      ctx.cwd,
+    );
   },
 };
 
@@ -89,7 +101,7 @@ const deno: Formatter = {
   // https://docs.deno.com/runtime/reference/cli/fmt/#configuring-the-formatter
   configFiles: ["deno.json", "deno.jsonc", { file: "deno.json", key: "fmt" }],
   async format(files, ctx) {
-    await spawnProcess("deno", ["fmt", ...files], ctx.cwd);
+    await spawnProcess("deno", ["fmt", "--permit-no-files", ...files], ctx.cwd);
   },
 };
 
@@ -102,7 +114,7 @@ const dprint: Formatter = {
     // NOTE: dprint could be installed in many ways globally, but for all the tools here, we assume
     // that they're installed locally in node_modules for now.
     const pm = await ctx.getPackageManager();
-    await packageManagerExecute(pm, ["dprint", "fmt", ...files], ctx.cwd);
+    await packageManagerExecute(pm, ["dprint", "fmt", "--allow-no-files", ...files], ctx.cwd);
   },
 };
 

tests/fixtures.test.ts

@@ -13,16 +13,6 @@ function canRunDeno() {
   });
 }
 
-// dprint requires an internet connection to download plugins (on the first run)
-async function canRunDprint() {
-  try {
-    await dns.lookup("plugins.dprint.dev");
-    return true;
-  } catch {
-    return false;
-  }
-}
-
 const cases: FormatterName[] = ["biome", "deno", "dprint", "oxfmt", "prettier"];
 
 test.for(cases)("detect and format %s fixture", { timeout: 10000 }, async (name, ctx) => {
@@ -32,9 +22,6 @@ test.for(cases)("detect and format %s fixture", { timeout: 10000 }, async (name,
     if (name === "deno" && !(await canRunDeno())) {
       ctx.skip("deno is not installed");
     }
-    if (name === "dprint" && !(await canRunDprint())) {
-      ctx.skip("no internet connection for dprint plugin download");
-    }
   }
 
   const fixtureTemplateDir = path.join(import.meta.dirname, "fixtures", name);
@@ -47,4 +34,8 @@ test.for(cases)("detect and format %s fixture", { timeout: 10000 }, async (name,
   const formatResult = await format(["file.ts"], { cwd: fixture.path, formatter: name });
   expect(formatResult).toBe(true);
   expect(await fixture.readFile("file.ts", "utf-8")).toMatchSnapshot();
+
+  // Formatting a missing file should be fine
+  const formatMissingResult = await format(["missing.ts"], { cwd: fixture.path, formatter: name });
+  expect(formatMissingResult).toBe(true);
 });

tests/format.test.ts

@@ -9,14 +9,33 @@ const mocks = vi.hoisted(() => ({
 vi.mock(import("tinyexec"), () => ({ exec: mocks.exec }));
 
 const cases: { formatter: FormatterName; expectedCommand: string[] }[] = [
-  { formatter: "prettier", expectedCommand: ["npx", "prettier", "--write", "file.ts"] },
+  {
+    formatter: "prettier",
+    expectedCommand: ["npx", "prettier", "--write", "--no-error-on-unmatched-pattern", "file.ts"],
+  },
   {
     formatter: "biome",
-    expectedCommand: ["npx", "@biomejs/biome", "format", "--write", "file.ts"],
+    expectedCommand: [
+      "npx",
+      "@biomejs/biome",
+      "format",
+      "--write",
+      "--no-errors-on-unmatched",
+      "file.ts",
+    ],
+  },
+  {
+    formatter: "oxfmt",
+    expectedCommand: ["npx", "oxfmt", "--write", "--no-error-on-unmatched-pattern", "file.ts"],
+  },
+  {
+    formatter: "deno",
+    expectedCommand: ["deno", "fmt", "--permit-no-files", "file.ts"],
+  },
+  {
+    formatter: "dprint",
+    expectedCommand: ["npx", "dprint", "fmt", "--allow-no-files", "file.ts"],
   },
-  { formatter: "oxfmt", expectedCommand: ["npx", "oxfmt", "--write", "file.ts"] },
-  { formatter: "deno", expectedCommand: ["deno", "fmt", "file.ts"] },
-  { formatter: "dprint", expectedCommand: ["npx", "dprint", "fmt", "file.ts"] },
 ];
 
 test.for(cases)("executes the correct command for $formatter", async (c) => {