Look for balanced curly brace end while searching for arguments.

jcabi · Aug 23, 2019 · 906e9c3 · 906e9c3
1 parent 259a5cf
commit 906e9c3
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Showing 2 changed files with 76 additions and 3 deletions.
diff --git a/src/main/java/com/jcabi/log/ConversionPattern.java b/src/main/java/com/jcabi/log/ConversionPattern.java
@@ -44,7 +44,7 @@ class ConversionPattern {
      * Regular expression for all matches.
      */
     private static final Pattern METAS = Pattern.compile(
-        "%color(?:-([a-z]+|[0-9]{1,3};[0-9]{1,3};[0-9]{1,3}))?\\{(.*?)\\}"
+        "%color(?:-([a-z]+|[0-9]{1,3};[0-9]{1,3};[0-9]{1,3}))?\\{"
     );
 
     /**
@@ -67,23 +67,52 @@ class ConversionPattern {
         this.colors = col;
     }
 
+    /**
+     * Find the matching closing curly brace while keeping any nested curly brace pairs balanced.
+     * @param start index of first character after the opening curly brace
+     * @return index of the closing curly brace, or -1 if not found
+     */
+    private static int findArgumentEnd(final String pattern, final int start) {
+        int openBraceCount = 1;
+        for (int index = start; index < pattern.length(); ++index) {
+            final char character = pattern.charAt(index);
+            if (character == '}') {
+                --openBraceCount;
+                if (openBraceCount == 0) {
+                    return index;
+                }
+            } else if (character == '{') {
+                ++openBraceCount;
+            }
+        }
+        return -1;
+    }
+
     /**
      * Generates the conversion pattern.
      * @return Conversion pattern
      */
     public String generate() {
+        String remainingPattern = this.pattern;
         final Matcher matcher = ConversionPattern.METAS.matcher(
-            this.pattern
+            remainingPattern
         );
         final StringBuffer buf = new StringBuffer(0);
         while (matcher.find()) {
+            final int argumentStart = matcher.end();
+            final int argumentEnd = findArgumentEnd(remainingPattern, argumentStart);
+            if (argumentEnd < 0) {
+                break;
+            }
             matcher.appendReplacement(buf, "");
             buf.append(ConversionPattern.csi())
                 .append(this.colors.ansi(matcher.group(1)))
                 .append('m')
-                .append(matcher.group(2))
+                .append(remainingPattern, argumentStart, argumentEnd)
                 .append(ConversionPattern.csi())
                 .append('m');
+            remainingPattern = remainingPattern.substring(argumentEnd + 1);
+            matcher.reset(remainingPattern);
         }
         matcher.appendTail(buf);
         return buf.toString();

diff --git a/src/test/java/com/jcabi/log/ConversionPatternTest.java b/src/test/java/com/jcabi/log/ConversionPatternTest.java
@@ -0,0 +1,44 @@
+package com.jcabi.log;
+
+import org.hamcrest.MatcherAssert;
+import org.hamcrest.Matchers;
+import org.junit.Test;
+
+public class ConversionPatternTest {
+    private static final String CSI = "\u001b\\[";
+    private static final Colors COLORS = new Colors();
+
+    @Test
+    public void testGenerateNoReplacement() {
+        MatcherAssert.assertThat(convert(""), Matchers.equalTo(""));
+        MatcherAssert.assertThat(convert("foo"), Matchers.equalTo("foo"));
+        MatcherAssert.assertThat(convert("%color"), Matchers.equalTo("%color"));
+        MatcherAssert.assertThat(convert("%color-"), Matchers.equalTo("%color-"));
+        MatcherAssert.assertThat(convert("%color{%c{1}foo"), Matchers.equalTo("%color{%c{1}foo"));
+    }
+
+    @Test
+    public void testGenerateEmpty() {
+        MatcherAssert.assertThat(convert("%color{}"), Matchers.equalTo(CSI + "?m" + CSI + "m"));
+    }
+
+    @Test
+    public void testGenerateSimple() {
+        MatcherAssert.assertThat(convert("%color{Hello World}"), Matchers.equalTo(CSI + "?mHello World" + CSI + "m"));
+        MatcherAssert.assertThat(convert("%color{Hello World}foo"), Matchers.equalTo(CSI + "?mHello World" + CSI + "mfoo"));
+
+        MatcherAssert.assertThat(convert("%color{Hello}%color{World}"), Matchers.equalTo(CSI + "?mHello" + CSI + "m" + CSI + "?mWorld" + CSI + "m"));
+    }
+
+    @Test
+    public void testGenerateCurlyBraces() {
+        MatcherAssert.assertThat(convert("%color{%c{1}}"), Matchers.equalTo(CSI + "?m%c{1}" + CSI + "m"));
+        MatcherAssert.assertThat(convert("%color{%c{1}}foo"), Matchers.equalTo(CSI + "?m%c{1}" + CSI + "mfoo"));
+        MatcherAssert.assertThat(convert("%color{%c1}}foo"), Matchers.equalTo(CSI + "?m%c1" + CSI + "m}foo"));
+        MatcherAssert.assertThat(convert("%color{%c{{{1}{2}}}}foo"), Matchers.equalTo(CSI + "?m%c{{{1}{2}}}" + CSI + "mfoo"));
+    }
+
+    private static String convert(final String pat) {
+        return new ConversionPattern(pat, COLORS).generate();
+    }
+}