graphql.parser.StringValueParsing Maven / Gradle / Ivy
package graphql.parser;
import graphql.Assert;
import graphql.Internal;
import graphql.language.SourceLocation;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Contains parsing code for the StringValue types in the grammar
*/
@Internal
public class StringValueParsing {
private final static String ESCAPED_TRIPLE_QUOTES = "\\\\\"\"\""; // ahh Java + Regex
private final static String THREE_QUOTES = "\"\"\"";
public static String parseTripleQuotedString(String strText) {
int end = strText.length() - 3;
String s = strText.substring(3, end);
s = s.replaceAll(ESCAPED_TRIPLE_QUOTES, THREE_QUOTES);
return removeIndentation(s);
}
/*
See https://github.com/facebook/graphql/pull/327/files#diff-fe406b08746616e2f5f00909488cce66R758
*/
public static String removeIndentation(String rawValue) {
String[] lines = rawValue.split("\\n");
Integer commonIndent = null;
for (int i = 0; i < lines.length; i++) {
if (i == 0) {
continue;
}
String line = lines[i];
int length = line.length();
int indent = leadingWhitespace(line);
if (indent < length) {
if (commonIndent == null || indent < commonIndent) {
commonIndent = indent;
}
}
}
List lineList = new ArrayList<>(Arrays.asList(lines));
if (commonIndent != null) {
for (int i = 0; i < lineList.size(); i++) {
String line = lineList.get(i);
if (i == 0) {
continue;
}
if (line.length() > commonIndent) {
line = line.substring(commonIndent);
lineList.set(i, line);
}
}
}
while (!lineList.isEmpty()) {
String line = lineList.get(0);
if (containsOnlyWhiteSpace(line)) {
lineList.remove(0);
} else {
break;
}
}
while (!lineList.isEmpty()) {
int endIndex = lineList.size() - 1;
String line = lineList.get(endIndex);
if (containsOnlyWhiteSpace(line)) {
lineList.remove(endIndex);
} else {
break;
}
}
StringBuilder formatted = new StringBuilder();
for (int i = 0; i < lineList.size(); i++) {
String line = lineList.get(i);
if (i == 0) {
formatted.append(line);
} else {
formatted.append("\n");
formatted.append(line);
}
}
return formatted.toString();
}
private static int leadingWhitespace(String str) {
int count = 0;
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (ch != ' ' && ch != '\t') {
break;
}
count++;
}
return count;
}
private static boolean containsOnlyWhiteSpace(String str) {
// according to graphql spec and graphql-js - this is the definition
return leadingWhitespace(str) == str.length();
}
public static String parseSingleQuotedString(String string, SourceLocation sourceLocation) {
StringWriter writer = new StringWriter(string.length() - 2);
int end = string.length() - 1;
for (int i = 1; i < end; i++) {
char c = string.charAt(i);
if (c != '\\') {
writer.write(c);
continue;
}
char escaped = string.charAt(i + 1);
i += 1;
switch (escaped) {
case '"':
writer.write('"');
continue;
case '/':
writer.write('/');
continue;
case '\\':
writer.write('\\');
continue;
case 'b':
writer.write('\b');
continue;
case 'f':
writer.write('\f');
continue;
case 'n':
writer.write('\n');
continue;
case 'r':
writer.write('\r');
continue;
case 't':
writer.write('\t');
continue;
case 'u':
i = UnicodeUtil.parseAndWriteUnicode(writer, string, i, sourceLocation);
continue;
default:
Assert.assertShouldNeverHappen();
}
}
return writer.toString();
}
public static String parseSingleQuotedString(String string) {
return parseSingleQuotedString(string, null);
}
}