[plsql] Add new sample rule AvoidTabCharacter

pmd-plsql/src/main/java/net/sourceforge/pmd/lang/plsql/rule/codestyle/AvoidTabCharacterRule.java

@@ -0,0 +1,38 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.plsql.rule.codestyle;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringReader;
+
+import net.sourceforge.pmd.lang.plsql.ast.ASTInput;
+import net.sourceforge.pmd.lang.plsql.rule.AbstractPLSQLRule;
+
+public class AvoidTabCharacterRule extends AbstractPLSQLRule {
+
+    public AvoidTabCharacterRule() {
+        addRuleChainVisit(ASTInput.class);
+    }
+
+    @Override
+    public Object visit(ASTInput node, Object data) {
+        try (BufferedReader in = new BufferedReader(new StringReader(node.getSourcecode()))) {
+            String line;
+            int lineNumber = 0;
+            while ((line = in.readLine()) != null) {
+                lineNumber++;
+                if (line.indexOf('\t') != -1) {
+                    addViolationWithMessage(data, null, "Tab characters are not allowed. Use spaces for intendation",
+                            lineNumber, lineNumber);
+                    break;
+                }
+            }
+        } catch (IOException e) {
+            throw new RuntimeException("Error while executing rule AvoidTabCharacter", e);
+        }
+        return data;
+    }
+}

pmd-plsql/src/main/resources/category/plsql/codestyle.xml

@@ -9,6 +9,24 @@
 Rules which enforce a specific coding style.
     </description>
 
+    <rule name="AvoidTabCharacter"
+          language="plsql"
+          since="6.13.0"
+          message="Avoid tab characters for indentation. Use spaces instead."
+          class="net.sourceforge.pmd.lang.plsql.rule.codestyle.AvoidTabCharacterRule"
+          externalInfoUrl="${pmd.website.baseurl}/pmd_rules_plsql_codestyle.html#avoidtabcharacter">
+        <description>
+This rule checks, that there are no tab characters (`\t`) in the source file.
+It reports only the first occurrence per file.
+
+Using tab characters for indentation is not recommended, since this requires that every developer
+uses the same tab with in their editor.
+
+This rule is the PMD equivalent of checkstyle's [FileTabCharacter](http://checkstyle.sourceforge.net/config_whitespace.html#FileTabCharacter) check.
+        </description>
+        <priority>3</priority>
+    </rule>
+
     <rule name="CodeFormat"
           language="plsql"
           since="6.9.0"

pmd-plsql/src/test/java/net/sourceforge/pmd/lang/plsql/rule/codestyle/AvoidTabCharacterTest.java

@@ -0,0 +1,11 @@
+/**
+ * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
+ */
+
+package net.sourceforge.pmd.lang.plsql.rule.codestyle;
+
+import net.sourceforge.pmd.testframework.PmdRuleTst;
+
+public class AvoidTabCharacterTest extends PmdRuleTst {
+    // no additional unit tests
+}

pmd-plsql/src/test/resources/net/sourceforge/pmd/lang/plsql/rule/codestyle/xml/AvoidTabCharacter.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<test-data
+    xmlns="http://pmd.sourceforge.net/rule-tests"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://pmd.sourceforge.net/rule-tests http://pmd.sourceforge.net/rule-tests_1_0_0.xsd">
+
+    <test-code>
+        <description>Using tabs - only the first tab character is reported</description>
+        <expected-problems>1</expected-problems>
+        <expected-linenumbers>2</expected-linenumbers>
+        <code><![CDATA[
+BEGIN
+	SELECT cmer_id
+		,version
+		,cmp_id
+	BULK COLLECT INTO v_cmer_ids
+		,v_versions
+		,v_cmp_ids
+	FROM cmer;
+END;
+/
+        ]]></code>
+        <source-type>plsql</source-type>
+    </test-code>
+
+    <test-code>
+        <description>No tabs</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+BEGIN
+    SELECT cmer_id
+        ,version
+        ,cmp_id
+    BULK COLLECT INTO v_cmer_ids
+        ,v_versions
+        ,v_cmp_ids
+    FROM cmer;
+END;
+/
+        ]]></code>
+        <source-type>plsql</source-type>
+    </test-code>
+</test-data>