chore: add StringsTest, TextUtilsTest

org.eclipse.tm4e.languageconfiguration/src/main/java/org/eclipse/tm4e/languageconfiguration/internal/utils/Strings.java

@@ -13,7 +13,7 @@
  *
  * Contributors:
  * - Microsoft Corporation: Initial code, written in TypeScript, licensed under MIT license
- * - Sebastian Thomschke - translation and adaptation to Java
+ * - Sebastian Thomschke (Vegard IT) - translation and adaptation to Java
  */
 package org.eclipse.tm4e.languageconfiguration.internal.utils;
 
@@ -32,50 +32,53 @@ public static String escapeRegExpCharacters(final String value) {
 	}
 
 	/**
-	 * @returns first index of the string that is not whitespace or -1 if string is empty or contains only whitespaces
+	 * @returns first index of the string that is not whitespace; or -1 if string is empty or contains only whitespaces.
 	 */
 	public static int firstNonWhitespaceIndex(final String text) {
 		for (int i = 0, len = text.length(); i < len; i++) {
 			final char ch = text.charAt(i);
-			if (!Character.isWhitespace(ch)) {
+			if (!Character.isWhitespace(ch))
 				return i;
-			}
 		}
 		return -1;
 	}
 
 	/**
-	 * @return the leading whitespace of the string. If the string contains only whitespaces, returns entire string.
+	 * @return the leading whitespace of the string; or the entire string if the string contains only whitespaces.
 	 */
 	public static String getLeadingWhitespace(final String searchIn) {
 		return getLeadingWhitespace(searchIn, 0, searchIn.length());
 	}
 
 	/**
-	 * @return the leading whitespace of the string. If the string contains only whitespaces, returns entire string.
+	 * @return the leading whitespace of the string; or the entire string if the string contains only whitespaces.
+	 */
+	public static String getLeadingWhitespace(final String searchIn, final int startAt) {
+		return getLeadingWhitespace(searchIn, startAt, searchIn.length());
+	}
+
+	/**
+	 * @return the leading whitespace of the string; or the entire string if the string contains only whitespaces.
 	 */
 	public static String getLeadingWhitespace(final String searchIn, final int startAt, final int endAt) {
 		for (int i = startAt; i < endAt; i++) {
-			final char ch = searchIn.charAt(endAt);
-			if (ch != ' ' && ch != '\t') {
+			final char ch = searchIn.charAt(i);
+			if (!Character.isWhitespace(ch))
 				return searchIn.substring(startAt, i);
-			}
 		}
 		return searchIn.substring(startAt, endAt);
 	}
 
 	/**
-	 * @return the last index of the string that is not whitespace.
-	 *         If the string is empty or contains only whitespaces, returns -1.
+	 * @return the last index of the string that is not whitespace; or -1 if string is empty or contains only whitespaces.
 	 *         Defaults to starting from the end of the string.
 	 */
 	public static int lastNonWhitespaceIndex(final String str) {
 		return lastNonWhitespaceIndex(str, str.length() - 1);
 	}
 
 	/**
-	 * @return the last index of the string that is not whitespace.
-	 *         If the string is empty or contains only whitespaces, returns -1.
+	 * @return the last index of the string that is not whitespace; or -1 if string is empty or contains only whitespaces.
 	 */
 	public static int lastNonWhitespaceIndex(final String str, final int startIndex) {
 		for (int i = startIndex; i >= 0; i--) {

org.eclipse.tm4e.languageconfiguration/src/main/java/org/eclipse/tm4e/languageconfiguration/internal/utils/TextEditorPrefs.java

@@ -23,14 +23,20 @@
 public final class TextEditorPrefs {
 
 	public static CursorConfiguration getCursorConfiguration(final @Nullable ITextEditor editor) {
-		final var editorPrefStore = editor == null ? null : editor.getAdapter(IPreferenceStore.class);
+		final var editorPrefStore = editor == null
+				? null
+				: editor.getAdapter(IPreferenceStore.class);
+
 		final var useSpacesPrefStore = editorPrefStore != null && editorPrefStore.contains(EDITOR_SPACES_FOR_TABS)
 				? editorPrefStore
 				: EditorsUI.getPreferenceStore();
+
 		final var tabWidthPrefStore = editorPrefStore != null && editorPrefStore.contains(EDITOR_TAB_WIDTH)
 				? editorPrefStore
 				: EditorsUI.getPreferenceStore();
-		return new CursorConfiguration(useSpacesPrefStore.getBoolean(EDITOR_SPACES_FOR_TABS),
+
+		return new CursorConfiguration(
+				useSpacesPrefStore.getBoolean(EDITOR_SPACES_FOR_TABS),
 				tabWidthPrefStore.getInt(EDITOR_TAB_WIDTH));
 	}
 

org.eclipse.tm4e.languageconfiguration/src/main/java/org/eclipse/tm4e/languageconfiguration/internal/utils/TextUtils.java

@@ -35,28 +35,6 @@ private static boolean isLegalLineDelimiter(final IDocument doc, final String de
 		return false;
 	}
 
-	/**
-	 * Returns the start of searchFor at the offset in the searchIn.
-	 * If the searchFor is not in the searchIn at the offset, returns -1.
-	 * <p>
-	 * Example:
-	 *
-	 * <pre>
-	 * text="apple banana", offset=8, string="banana" -> returns 6
-	 * </pre>
-	 */
-	public static int startIndexOfOffsetTouchingString(final String searchIn, final int offset, final String searchFor) {
-		final int start = Math.max(0, offset - searchFor.length());
-		int end = offset + searchFor.length();
-		end = end >= searchIn.length() ? searchIn.length() : end;
-		try {
-			final int indexInSubtext = searchIn.substring(start, end).indexOf(searchFor);
-			return indexInSubtext == -1 ? -1 : start + indexInSubtext;
-		} catch (final IndexOutOfBoundsException e) {
-			return -1;
-		}
-	}
-
 	public static String getIndentationFromWhitespace(final String whitespace, final CursorConfiguration cursorCfg) {
 		final var tab = "\t";
 		int indentOffset = 0;
@@ -80,7 +58,7 @@ public static String getIndentationFromWhitespace(final String whitespace, final
 
 	/**
 	 * @see <a href=
-	 *      "https://github.com/microsoft/vscode/blob/ba2cf46e20df3edf77bdd905acde3e175d985f70/src/vs/base/common/strings.ts">
+	 *      "https://github.com/microsoft/vscode/blob/ba2cf46e20df3edf77bdd905acde3e175d985f70/src/vs/editor/common/languages/languageConfigurationRegistry.ts">
 	 *      github.com/microsoft/vscode/blob/main/src/vs/editor/common/languages/languageConfigurationRegistry.ts</a>
 	 */
 	public static String getIndentationAtPosition(final IDocument doc, final int offset) {
@@ -120,6 +98,12 @@ private static int findEndOfWhiteSpace(final IDocument doc, final int startAt, f
 		return endAt;
 	}
 
+	public static String getLeadingWhitespace(final IDocument doc, int lineIndex) throws BadLocationException {
+		final int lineStartOffset = doc.getLineOffset(lineIndex);
+		final int lineLength = doc.getLineLength(lineIndex);
+		return doc.get(lineStartOffset, findEndOfWhiteSpace(doc, lineStartOffset, lineStartOffset + lineLength) - lineStartOffset);
+	}
+
 	/**
 	 * Determines if all the characters at any offset of the specified document line are the whitespace characters.
 	 *
@@ -145,6 +129,22 @@ public static boolean isBlankLine(final IDocument doc, final int lineIndex) {
 		return true;
 	}
 
+	public static boolean isEmptyLine(final IDocument doc, final int lineIndex) {
+		try {
+			final int lineLength = doc.getLineLength(lineIndex);
+			if (lineLength > 2)
+				return false;
+			if (lineLength == 0)
+				return true;
+
+			final int lineOffset = doc.getLineOffset(lineIndex);
+			return isLegalLineDelimiter(doc, doc.get(lineOffset, lineLength));
+		} catch (final BadLocationException e) {
+			// Ignore, forcing a positive result
+			return true;
+		}
+	}
+
 	private TextUtils() {
 	}
 }