Fix Slf4jLogShouldBeConstant to preserve format specifiers with width, alignment, and precision. (#239)

Author: motlin

src/main/java/org/openrewrite/java/logging/slf4j/Slf4jLogShouldBeConstant.java

@@ -31,13 +31,15 @@
 import org.openrewrite.java.tree.TypeUtils;
 
 import java.util.*;
+import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 public class Slf4jLogShouldBeConstant extends Recipe {
 
     private static final String SLF4J_FORMAT_SPECIFIER = "{}";
     private static final Pattern SLF4J_FORMAT_SPECIFIER_PATTERN = Pattern.compile("\\{}");
-    private static final Pattern FORMAT_SPECIFIER_PATTERN = Pattern.compile("%[\\d.]*[dfscbBhHn%]");
+    private static final Pattern FORMAT_SPECIFIER_PATTERN = Pattern.compile("%[-#+ 0,(\\d+]*[\\d.]*[dfscbBhHn%]");
+    private static final Pattern SIMPLE_FORMAT_SPECIFIER_PATTERN = Pattern.compile("%[dfscbBhHn%]");
 
     // A regular expression that matches index specifiers like '%2$s', '%1$s', etc.
     private static final Pattern INDEXED_FORMAT_SPECIFIER_PATTERN = Pattern.compile("%(\\d+\\$)[a-zA-Z]");
@@ -78,7 +80,7 @@ public J visitMethodInvocation(J.MethodInvocation method, ExecutionContext ctx)
                             }
 
                             String strFormat = Objects.requireNonNull(((J.Literal) stringFormat.getArguments().get(0)).getValue()).toString();
-                            if (containsIndexFormatSpecifier(strFormat) || containsCombinedFormatSpecifiers(strFormat)) {
+                            if (containsIndexFormatSpecifier(strFormat) || containsCombinedFormatSpecifiers(strFormat) || containsComplexFormatSpecifiers(strFormat)) {
                                 return method;
                             }
                             String updatedStrFormat = replaceFormatSpecifier(strFormat, SLF4J_FORMAT_SPECIFIER);
@@ -133,4 +135,18 @@ private static boolean containsIndexFormatSpecifier(String str) {
         }
         return INDEXED_FORMAT_SPECIFIER_PATTERN.matcher(str).find();
     }
+
+    private static boolean containsComplexFormatSpecifiers(String str) {
+        if (StringUtils.isNullOrEmpty(str)) {
+            return false;
+        }
+        Matcher matcher = FORMAT_SPECIFIER_PATTERN.matcher(str);
+        while (matcher.find()) {
+            String specifier = matcher.group();
+            if (!SIMPLE_FORMAT_SPECIFIER_PATTERN.matcher(specifier).matches()) {
+                return true;
+            }
+        }
+        return false;
+    }
 }

src/test/java/org/openrewrite/java/logging/slf4j/Slf4jLogShouldBeConstantTest.java

@@ -49,15 +49,6 @@ void method() {
                       log.info(String.format("The first argument is '%d', and the second argument is '%.2f'.", 1, 2.3333));
                   }
               }
-              """,
-            """
-              import org.slf4j.Logger;
-              class A {
-                  Logger log;
-                  void method() {
-                      log.info("The first argument is '{}', and the second argument is '{}'.", 1, 2.3333);
-                  }
-              }
               """
           )
         );
@@ -372,4 +363,57 @@ void test() {
         );
     }
 
+    @Test
+    void noChangeWithWidth() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              import org.slf4j.Logger;
+              class A {
+                  Logger log;
+                  void method() {
+                      log.info(String.format("%10s", "test"));
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void noChangeWithLeftAlignment() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              import org.slf4j.Logger;
+              class A {
+                  Logger log;
+                  void method() {
+                      log.info(String.format("%-10s", "test"));
+                  }
+              }
+              """
+          )
+        );
+    }
+
+    @Test
+    void noChangeWithPrecision() {
+        //language=java
+        rewriteRun(
+          java(
+            """
+              import org.slf4j.Logger;
+              class A {
+                  Logger log;
+                  void method() {
+                      log.info(String.format("%.2f", 1.2345));
+                  }
+              }
+              """
+          )
+        );
+    }
 }