feat: support range format in cli

src/clang-format-cli.js

@@ -2,7 +2,13 @@
 import { readFileSync } from "node:fs";
 import { readFile, writeFile } from "node:fs/promises";
 import { parseArgs } from "node:util";
-import init, { format, version } from "./clang-format-node.js";
+import init, {
+    format,
+    format_byte_range,
+    format_line_range,
+    set_fallback_style,
+    version,
+} from "./clang-format-node.js";
 
 await init();
 
@@ -71,26 +77,104 @@ for (const token of tokens) {
     }
 }
 
-let files = positionals;
+let fileNames = positionals;
 if (values.files) {
     const ExternalFileOfFiles = await readFile(values.files, {
         encoding: "utf-8",
     });
-    files = files.concat(ExternalFileOfFiles.split("\n").filter(Boolean));
+    fileNames = fileNames.concat(
+        ExternalFileOfFiles.split("\n").filter(Boolean),
+    );
 }
 
-if (files.length === 0) {
-    files = ["-"];
+if (fileNames.length === 0) {
+    fileNames = ["-"];
 }
 
-// TODO: handle lines, offset and length
-for (const file of files) {
-    if (file === "-" && values.inplace) {
-        console.error("error: cannot use -i when reading from stdin.");
-        process.exit(1);
+if (values["fallback-style"]) {
+    set_fallback_style(values["fallback-style"]);
+}
+
+if (
+    fileNames.length !== 1 &&
+    (!empty(values.offset) || !empty(values.length) || !empty(values.lines))
+) {
+    console.error(
+        "error: -offset, -length and -lines can only be used for single file",
+    );
+    process.exit(1);
+}
+
+if (!empty(values.lines) && (!empty(values.offset) || !empty(values.length))) {
+    console.error("error: cannot use -lines with -offset/-length");
+    process.exit(1);
+}
+
+if (!empty(values.lines)) {
+    const [file] = fileNames;
+    const content = await get_file_or_stdin(file);
+
+    const range = [];
+    for (const line of values.lines) {
+        const [form_line_text, to_line_text] = line.split(":");
+        const [from_line, to_line] = [
+            Number.parseInt(form_line_text, 10),
+            Number.parseInt(to_line_text, 10),
+        ];
+        if (!Number.isFinite(from_line) || !Number.isFinite(to_line)) {
+            console.error("error: invalid <start line>:<end line> pair");
+            process.exit(1);
+        }
+        range.push([from_line, to_line]);
+    }
+
+    const formatted = format_line_range(content, range, file, values.style);
+
+    if (values.inplace) {
+        if (content !== formatted) {
+            await writeFile(file, formatted, { encoding: "utf-8" });
+        }
+    } else {
+        console.log(formatted);
+    }
+    process.exit(0);
+}
+
+if (values.offset.length !== values.length.length) {
+    console.error("error: number of -offset and -length arguments must match");
+    process.exit(1);
+}
+
+if (!empty(values.offset)) {
+    const [file] = fileNames;
+    const content = await get_file_or_stdin(file);
+
+    const range = [];
+    for (let i = 0; i < values.offset.length; ++i) {
+        const offset = Number.parseInt(values.offset[i], 10);
+        const length = Number.parseInt(values.length[i], 10);
+        if (!Number.isFinite(offset) || !Number.isFinite(length)) {
+            console.error("error: invalid <offset>:<length> pair");
+            process.exit(1);
+        }
+        range.push([offset, length]);
     }
 
-    const content = await getFileOrSTDIN(file);
+    const formatted = format_byte_range(content, range, file, values.style);
+
+    if (values.inplace) {
+        if (content !== formatted) {
+            await writeFile(file, formatted, { encoding: "utf-8" });
+        }
+    } else {
+        console.log(formatted);
+    }
+
+    process.exit(0);
+}
+
+for (const file of fileNames) {
+    const content = await get_file_or_stdin(file);
     // TODO: search .clang-format on disk if values.style is not set
     const formatted = format(content, file, values.style);
     if (values.inplace) {
@@ -102,8 +186,16 @@ for (const file of files) {
     }
 }
 
-async function getFileOrSTDIN(fileName) {
+function empty(array) {
+    return array.length === 0;
+}
+
+async function get_file_or_stdin(fileName) {
     if (fileName === "-") {
+        if (values.inplace) {
+            console.error("error: cannot use -i when reading from stdin");
+            process.exit(1);
+        }
         return readFileSync(0, { encoding: "utf-8" });
     }
     return await readFile(fileName, { encoding: "utf-8" });

src/clang-format.d.ts

@@ -172,3 +172,5 @@ export declare function formatByteRange(
 ): string;
 
 export declare function version(): string;
+
+export declare function set_fallback_style(style: Style): void;

src/lib.cc

@@ -272,6 +272,10 @@ static auto format_line(const std::string str,
     return clang::format::format_range(str, assumedFileName, style, true, std::move(ranges));
 }
 
+static auto set_fallback_style(const std::string style) -> void {
+    FallbackStyle = style;
+}
+
 using namespace emscripten;
 
 EMSCRIPTEN_BINDINGS(my_module) {
@@ -285,6 +289,7 @@ EMSCRIPTEN_BINDINGS(my_module) {
         "format_byte", &format_byte);
     function<Result, const std::string, const std::string, const std::string, const std::vector<unsigned>>(
         "format_line", &format_line);
+    function<void, const std::string>("set_fallback_style", &set_fallback_style);
 }
 
 auto main(int argc, const char** argv) -> int {

src/template.js

@@ -52,6 +52,11 @@ export function version() {
     assert_init();
 }
 
+export function set_fallback_style(style) {
+    assert_init();
+    wasm.set_fallback_style(style);
+}
+
 function unwrap(result) {
     const { error, content } = result;
     if (error) {