From 7b17632caa177e92ecd3234fe505e0f8b4cc5f45 Mon Sep 17 00:00:00 2001
From: ascopes <73482956+ascopes@users.noreply.github.com>
Date: Sun, 21 Apr 2024 12:23:53 +0100
Subject: [PATCH] Make Shlex emit line continutations

---
 .../protobufmavenplugin/utils/Shlex.java      | 55 ++++++++++++++-----
 .../protobufmavenplugin/utils/ShlexTest.java  | 22 +++++++-
 2 files changed, 60 insertions(+), 17 deletions(-)

diff --git a/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/utils/Shlex.java b/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/utils/Shlex.java
index a0125c70..a5d520c7 100644
--- a/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/utils/Shlex.java
+++ b/protobuf-maven-plugin/src/main/java/io/github/ascopes/protobufmavenplugin/utils/Shlex.java
@@ -16,7 +16,7 @@
 
 package io.github.ascopes.protobufmavenplugin.utils;
 
-import java.util.function.BiConsumer;
+import java.util.function.Function;
 
 /**
  * Shell/batch file quoting.
@@ -24,25 +24,35 @@
  * <p>Losely based on Python's {@code shlex} module.
  *
  * <p>This is far from perfect but should work in the majority of use cases
- * to ensure scripts do not interpret special characters in paths in strange and unexpected ways.
+ * to ensure scripts do not interpret special characters in paths in strange
+ * and unexpected ways.
+ *
+ * <p>Long lines will be split up with line continuations.
  *
  * @author Ashley Scopes
  */
 public final class Shlex {
 
+  private static final int LINE_LENGTH_TARGET = 99;
+  private static final String INDENT = " ".repeat(4);
+
   private Shlex() {
     // Static-only class
   }
 
   public static String quoteShellArgs(Iterable<String> args) {
-    return quote(args, Shlex::quoteShellArg);
+    return quote(args, Shlex::quoteShellArg, " \\\n");
   }
 
   public static String quoteBatchArgs(Iterable<String> args) {
-    return quote(args, Shlex::quoteBatchArg);
+    return quote(args, Shlex::quoteBatchArg, " ^\r\n");
   }
 
-  private static String quote(Iterable<String> args, BiConsumer<StringBuilder, String> quoter) {
+  private static String quote(
+      Iterable<String> args,
+      Function<String, String> quoter,
+      String continuation
+  ) {
     var iter = args.iterator();
 
     if (!iter.hasNext()) {
@@ -50,23 +60,34 @@ private static String quote(Iterable<String> args, BiConsumer<StringBuilder, Str
       return "";
     }
 
-    var sb = new StringBuilder();
-    quoter.accept(sb, iter.next());
+    var sb = new StringBuilder(quoter.apply(iter.next()));
+    var lineLength = sb.length();
 
     while (iter.hasNext()) {
-      sb.append(' ');
-      quoter.accept(sb, iter.next());
+      var next = quoter.apply(iter.next());
+
+      if (lineLength + next.length() >= LINE_LENGTH_TARGET) {
+        sb.append(continuation);
+        lineLength = INDENT.length();
+        sb.append(INDENT);
+      } else {
+        sb.append(" ");
+        lineLength += 1;
+      }
+
+      sb.append(next);
+      lineLength += next.length();
     }
 
     return sb.toString();
   }
 
-  private static void quoteShellArg(StringBuilder sb, String arg) {
+  private static String quoteShellArg(String arg) {
     if (isSafe(arg)) {
-      sb.append(arg);
-      return;
+      return arg;
     }
 
+    var sb = new StringBuilder();
     sb.append('\'');
     for (var i = 0; i < arg.length(); ++i) {
       var c = arg.charAt(i);
@@ -89,14 +110,16 @@ private static void quoteShellArg(StringBuilder sb, String arg) {
       }
     }
     sb.append('\'');
+
+    return sb.toString();
   }
 
-  private static void quoteBatchArg(StringBuilder sb, String arg) {
+  private static String quoteBatchArg(String arg) {
     if (isSafe(arg)) {
-      sb.append(arg);
-      return;
+      return arg;
     }
 
+    var sb = new StringBuilder();
     for (var i = 0; i < arg.length(); ++i) {
       var c = arg.charAt(i);
       switch (c) {
@@ -121,6 +144,8 @@ private static void quoteBatchArg(StringBuilder sb, String arg) {
           break;
       }
     }
+
+    return sb.toString();
   }
 
   private static boolean isSafe(String arg) {
diff --git a/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/utils/ShlexTest.java b/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/utils/ShlexTest.java
index 33e47db6..567cde68 100644
--- a/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/utils/ShlexTest.java
+++ b/protobuf-maven-plugin/src/test/java/io/github/ascopes/protobufmavenplugin/utils/ShlexTest.java
@@ -85,7 +85,16 @@ static Stream<Arguments> quoteShellArgsTestCases() {
         arguments(list("'potato'"), "''\"'\"'potato'\"'\"''"),
         arguments(list("foo\nbar", "baz"), "'foo'$'\\n''bar' baz"),
         arguments(list("foo\rbar", "baz"), "'foo'$'\\r''bar' baz"),
-        arguments(list("foo\tbar", "baz"), "'foo'$'\\t''bar' baz")
+        arguments(list("foo\tbar", "baz"), "'foo'$'\\t''bar' baz"),
+        arguments(
+            list("a".repeat(100), "b".repeat(100), "c".repeat(100)),
+            String.join(
+                " \\\n    ",
+                "a".repeat(100),
+                "b".repeat(100),
+                "c".repeat(100)
+            )
+        )
     );
   }
 
@@ -115,7 +124,16 @@ static Stream<Arguments> quoteBatchArgsTestCases() {
         arguments(list("<"), "^<"),
         arguments(list(">"), "^>"),
         arguments(list("|"), "^|"),
-        arguments(list("100% complete", "0% incomplete"), "100%%^ complete 0%%^ incomplete")
+        arguments(list("100% complete", "0% incomplete"), "100%%^ complete 0%%^ incomplete"),
+        arguments(
+            list("a".repeat(100), "b".repeat(100), "c".repeat(100)),
+            String.join(
+                " ^\r\n    ",
+                "a".repeat(100),
+                "b".repeat(100),
+                "c".repeat(100)
+            )
+        )
     );
   }