graphql.language.AstPrinter Maven / Gradle / Ivy
package graphql.language;
import graphql.AssertException;
import graphql.PublicApi;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import static graphql.Assert.assertTrue;
import static graphql.util.EscapeUtil.escapeJsonString;
import static java.lang.String.valueOf;
import static java.util.stream.Collectors.joining;
/**
* This can take graphql language AST and print it out as a string
*/
@SuppressWarnings("UnnecessaryLocalVariable")
@PublicApi
public class AstPrinter {
private final Map, NodePrinter> printers = new LinkedHashMap<>();
private final boolean compactMode;
private AstPrinter(boolean compactMode) {
this.compactMode = compactMode;
printers.put(Argument.class, argument());
printers.put(ArrayValue.class, value());
printers.put(BooleanValue.class, value());
printers.put(NullValue.class, value());
printers.put(Directive.class, directive());
printers.put(DirectiveDefinition.class, directiveDefinition());
printers.put(DirectiveLocation.class, directiveLocation());
printers.put(Document.class, document());
printers.put(EnumTypeDefinition.class, enumTypeDefinition());
printers.put(EnumTypeExtensionDefinition.class, enumTypeExtensionDefinition());
printers.put(EnumValue.class, enumValue());
printers.put(EnumValueDefinition.class, enumValueDefinition());
printers.put(Field.class, field());
printers.put(FieldDefinition.class, fieldDefinition());
printers.put(FloatValue.class, value());
printers.put(FragmentDefinition.class, fragmentDefinition());
printers.put(FragmentSpread.class, fragmentSpread());
printers.put(InlineFragment.class, inlineFragment());
printers.put(InputObjectTypeDefinition.class, inputObjectTypeDefinition());
printers.put(InputObjectTypeExtensionDefinition.class, inputObjectTypeExtensionDefinition());
printers.put(InputValueDefinition.class, inputValueDefinition());
printers.put(InterfaceTypeDefinition.class, interfaceTypeDefinition());
printers.put(InterfaceTypeExtensionDefinition.class, interfaceTypeExtensionDefinition());
printers.put(IntValue.class, value());
printers.put(ListType.class, type());
printers.put(NonNullType.class, type());
printers.put(ObjectField.class, objectField());
printers.put(ObjectTypeDefinition.class, objectTypeDefinition());
printers.put(ObjectTypeExtensionDefinition.class, objectTypeExtensionDefinition());
printers.put(ObjectValue.class, value());
printers.put(OperationDefinition.class, operationDefinition());
printers.put(OperationTypeDefinition.class, operationTypeDefinition());
printers.put(ScalarTypeDefinition.class, scalarTypeDefinition());
printers.put(ScalarTypeExtensionDefinition.class, scalarTypeExtensionDefinition());
printers.put(SchemaDefinition.class, schemaDefinition());
printers.put(SchemaExtensionDefinition.class, schemaExtensionDefinition());
printers.put(SelectionSet.class, selectionSet());
printers.put(StringValue.class, value());
printers.put(TypeName.class, type());
printers.put(UnionTypeDefinition.class, unionTypeDefinition());
printers.put(UnionTypeExtensionDefinition.class, unionTypeExtensionDefinition());
printers.put(VariableDefinition.class, variableDefinition());
printers.put(VariableReference.class, variableReference());
}
private NodePrinter argument() {
if (compactMode) {
return (out, node) -> out.printf("%s:%s", node.getName(), value(node.getValue()));
}
return (out, node) -> out.printf("%s: %s", node.getName(), value(node.getValue()));
}
private NodePrinter document() {
if (compactMode) {
return (out, node) -> out.printf("%s", join(node.getDefinitions(), " "));
}
return (out, node) -> out.printf("%s\n", join(node.getDefinitions(), "\n\n"));
}
private NodePrinter directive() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
String arguments = wrap("(", join(node.getArguments(), argSep), ")");
out.printf("@%s%s", node.getName(), arguments);
};
}
private NodePrinter directiveDefinition() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
out.printf("%s", description(node));
String arguments = wrap("(", join(node.getInputValueDefinitions(), argSep), ")");
String locations = join(node.getDirectiveLocations(), " | ");
String repeatable = node.isRepeatable() ? "repeatable " : "";
out.printf("directive @%s%s %son %s", node.getName(), arguments, repeatable, locations);
};
}
private NodePrinter directiveLocation() {
return (out, node) -> out.print(node.getName());
}
private NodePrinter enumTypeDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s",
spaced(
"enum",
node.getName(),
directives(node.getDirectives()),
block(node.getEnumValueDefinitions())
));
};
}
private NodePrinter enumValue() {
return (out, node) -> out.printf("%s", node.getName());
}
private NodePrinter enumValueDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s",
spaced(
node.getName(),
directives(node.getDirectives())
));
};
}
private NodePrinter field() {
final String argSep = compactMode ? "," : ", ";
final String aliasSuffix = compactMode ? ":" : ": ";
return (out, node) -> {
String alias = wrap("", node.getAlias(), aliasSuffix);
String name = node.getName();
String arguments = wrap("(", join(node.getArguments(), argSep), ")");
String directives = directives(node.getDirectives());
String selectionSet = node(node.getSelectionSet());
out.printf("%s", spaced(
alias + name + arguments,
directives,
selectionSet
));
};
}
private NodePrinter fieldDefinition() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
String args;
if (hasDescription(node.getInputValueDefinitions()) && !compactMode) {
out.printf("%s", description(node));
args = join(node.getInputValueDefinitions(), "\n");
out.printf("%s", node.getName() +
wrap("(\n", args, ")") +
": " +
spaced(
type(node.getType()),
directives(node.getDirectives())
)
);
} else {
args = join(node.getInputValueDefinitions(), argSep);
out.printf("%s", node.getName() +
wrap("(", args, ")") +
": " +
spaced(
type(node.getType()),
directives(node.getDirectives())
)
);
}
};
}
private boolean hasDescription(List nodes) {
return nodes.stream().filter(it -> it instanceof AbstractDescribedNode).anyMatch(it -> ((AbstractDescribedNode) it).getDescription() != null);
}
private NodePrinter fragmentDefinition() {
return (out, node) -> {
String name = node.getName();
String typeCondition = type(node.getTypeCondition());
String directives = directives(node.getDirectives());
String selectionSet = node(node.getSelectionSet());
out.printf("fragment %s on %s ", name, typeCondition);
out.printf("%s", directives + selectionSet);
};
}
private NodePrinter fragmentSpread() {
return (out, node) -> {
String name = node.getName();
String directives = directives(node.getDirectives());
out.printf("...%s%s", name, directives);
};
}
private NodePrinter inlineFragment() {
return (out, node) -> {
TypeName typeName = node.getTypeCondition();
//Inline fragments may not have a type condition
String typeCondition = typeName == null ? "" : wrap("on ", type(typeName), "");
String directives = directives(node.getDirectives());
String selectionSet = node(node.getSelectionSet());
out.printf("%s", spaced(
"...",
typeCondition,
directives,
selectionSet
));
};
}
private NodePrinter inputObjectTypeDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s", spaced(
"input",
node.getName(),
directives(node.getDirectives()),
block(node.getInputValueDefinitions())
)
);
};
}
private NodePrinter inputValueDefinition() {
String nameTypeSep = compactMode ? ":" : ": ";
String defaultValueEquals = compactMode ? "=" : "= ";
return (out, node) -> {
Value defaultValue = node.getDefaultValue();
out.printf("%s", description(node));
out.printf("%s", spaced(
node.getName() + nameTypeSep + type(node.getType()),
wrap(defaultValueEquals, defaultValue, ""),
directives(node.getDirectives())
)
);
};
}
private NodePrinter interfaceTypeDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s", spaced(
"interface",
node.getName(),
wrap("implements ", join(node.getImplements(), " & "), ""),
directives(node.getDirectives()),
block(node.getFieldDefinitions())
)
);
};
}
private NodePrinter objectField() {
String nameValueSep = compactMode ? ":" : " : ";
return (out, node) -> out.printf("%s%s%s", node.getName(), nameValueSep, value(node.getValue()));
}
private NodePrinter operationDefinition() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
String op = node.getOperation().toString().toLowerCase();
String name = node.getName();
String varDefinitions = wrap("(", join(nvl(node.getVariableDefinitions()), argSep), ")");
String directives = directives(node.getDirectives());
String selectionSet = node(node.getSelectionSet());
// Anonymous queries with no directives or variable definitions can use
// the query short form.
if (isEmpty(name) && isEmpty(directives) && isEmpty(varDefinitions) && op.equals("QUERY")) {
out.printf("%s", selectionSet);
} else {
out.printf("%s", spaced(op, smooshed(name, varDefinitions), directives, selectionSet));
}
};
}
private NodePrinter operationTypeDefinition() {
String nameTypeSep = compactMode ? ":" : ": ";
return (out, node) -> out.printf("%s%s%s", node.getName(), nameTypeSep, type(node.getTypeName()));
}
private NodePrinter objectTypeDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s", spaced(
"type",
node.getName(),
wrap("implements ", join(node.getImplements(), " & "), ""),
directives(node.getDirectives()),
block(node.getFieldDefinitions())
));
};
}
private NodePrinter selectionSet() {
return (out, node) -> {
out.printf("%s", block(node.getSelections()));
};
}
private NodePrinter scalarTypeDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s", spaced(
"scalar",
node.getName(),
directives(node.getDirectives())));
};
}
private NodePrinter schemaDefinition() {
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s", spaced(
"schema",
directives(node.getDirectives()),
block(node.getOperationTypeDefinitions())
));
};
}
private NodePrinter type() {
return (out, node) -> out.print(type(node));
}
private String type(Type type) {
if (type instanceof NonNullType) {
NonNullType inner = (NonNullType) type;
return wrap("", type(inner.getType()), "!");
} else if (type instanceof ListType) {
ListType inner = (ListType) type;
return wrap("[", type(inner.getType()), "]");
} else {
TypeName inner = (TypeName) type;
return inner.getName();
}
}
private NodePrinter objectTypeExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, ObjectTypeDefinition.class));
}
private NodePrinter enumTypeExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, EnumTypeDefinition.class));
}
private NodePrinter interfaceTypeExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, InterfaceTypeDefinition.class));
}
private NodePrinter unionTypeExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, UnionTypeDefinition.class));
}
private NodePrinter scalarTypeExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, ScalarTypeDefinition.class));
}
private NodePrinter inputObjectTypeExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, InputObjectTypeDefinition.class));
}
private NodePrinter schemaExtensionDefinition() {
return (out, node) -> out.printf("extend %s", node(node, SchemaDefinition.class));
}
private NodePrinter unionTypeDefinition() {
String barSep = compactMode ? "|" : " | ";
String equals = compactMode ? "=" : "= ";
return (out, node) -> {
out.printf("%s", description(node));
out.printf("%s", spaced(
"union",
node.getName(),
directives(node.getDirectives()),
equals + join(node.getMemberTypes(), barSep)
));
};
}
private NodePrinter variableDefinition() {
String nameTypeSep = compactMode ? ":" : ": ";
String defaultValueEquals = compactMode ? "=" : " = ";
return (out, node) -> out.printf("$%s%s%s%s%s",
node.getName(),
nameTypeSep,
type(node.getType()),
wrap(defaultValueEquals, node.getDefaultValue(), ""),
directives(node.getDirectives())
);
}
private NodePrinter variableReference() {
return (out, node) -> out.printf("$%s", node.getName());
}
private String node(Node node) {
return node(node, null);
}
private String node(Node node, Class startClass) {
if (startClass != null) {
assertTrue(startClass.isInstance(node), () -> "The starting class must be in the inherit tree");
}
StringWriter sw = new StringWriter();
PrintWriter out = new PrintWriter(sw);
NodePrinter printer = _findPrinter(node, startClass);
printer.print(out, node);
return sw.toString();
}
@SuppressWarnings("unchecked")
private NodePrinter _findPrinter(Node node) {
return _findPrinter(node, null);
}
private NodePrinter _findPrinter(Node node, Class startClass) {
if (node == null) {
return (out, type) -> {
};
}
Class clazz = startClass != null ? startClass : node.getClass();
while (clazz != Object.class) {
NodePrinter nodePrinter = printers.get(clazz);
if (nodePrinter != null) {
//noinspection unchecked
return nodePrinter;
}
clazz = clazz.getSuperclass();
}
throw new AssertException(String.format("We have a missing printer implementation for %s : report a bug!", clazz));
}
private boolean isEmpty(List list) {
return list == null || list.isEmpty();
}
private boolean isEmpty(String s) {
return s == null || s.trim().length() == 0;
}
private List nvl(List list) {
return list != null ? list : Collections.emptyList();
}
private NodePrinter value() {
return (out, node) -> out.print(value(node));
}
private String value(Value value) {
String argSep = compactMode ? "," : ", ";
if (value instanceof IntValue) {
return valueOf(((IntValue) value).getValue());
} else if (value instanceof FloatValue) {
return valueOf(((FloatValue) value).getValue());
} else if (value instanceof StringValue) {
return wrap("\"", escapeJsonString(((StringValue) value).getValue()), "\"");
} else if (value instanceof EnumValue) {
return valueOf(((EnumValue) value).getName());
} else if (value instanceof BooleanValue) {
return valueOf(((BooleanValue) value).isValue());
} else if (value instanceof NullValue) {
return "null";
} else if (value instanceof ArrayValue) {
return "[" + join(((ArrayValue) value).getValues(), argSep) + "]";
} else if (value instanceof ObjectValue) {
return "{" + join(((ObjectValue) value).getObjectFields(), argSep) + "}";
} else if (value instanceof VariableReference) {
return "$" + ((VariableReference) value).getName();
}
return "";
}
private String description(Node node) {
Description description = ((AbstractDescribedNode) node).getDescription();
if (description == null || description.getContent() == null || compactMode) {
return "";
}
String s;
boolean startNewLine = description.getContent().charAt(0) == '\n';
if (description.isMultiLine()) {
s = "\"\"\"" + (startNewLine ? "" : "\n") + description.getContent() + "\n\"\"\"\n";
} else {
s = "\"" + description.getContent() + "\"\n";
}
return s;
}
private String directives(List directives) {
return join(nvl(directives), " ");
}
private String join(List nodes, String delim) {
return join(nodes, delim, "", "");
}
@SuppressWarnings("SameParameterValue")
private String join(List nodes, String delim, String prefix, String suffix) {
String s = nvl(nodes).stream().map(this::node).collect(joining(delim, prefix, suffix));
return s;
}
private String spaced(String... args) {
return join(" ", args);
}
private String smooshed(String... args) {
return join("", args);
}
private String join(String delim, String... args) {
String s = Arrays.stream(args).filter(arg -> !isEmpty(arg)).collect(joining(delim));
return s;
}
String wrap(String start, String maybeString, String end) {
if (isEmpty(maybeString)) {
if (start.equals("\"") && end.equals("\"")) {
return "\"\"";
}
return "";
}
return start + maybeString + (!isEmpty(end) ? end : "");
}
private String block(List nodes) {
if (isEmpty(nodes)) {
return "{}";
}
if (compactMode) {
return "{"
+ join(nodes, " ")
+ "}";
}
return indent("{\n"
+ join(nodes, "\n"))
+ "\n}";
}
private String indent(String maybeString) {
if (isEmpty(maybeString)) {
return "";
}
maybeString = maybeString.replaceAll("\\n", "\n ");
return maybeString;
}
@SuppressWarnings("SameParameterValue")
String wrap(String start, Node maybeNode, String end) {
if (maybeNode == null) {
return "";
}
return start + node(maybeNode) + (isEmpty(end) ? "" : end);
}
/**
* This will pretty print the AST node in graphql language format
*
* @param node the AST node to print
*
* @return the printed node in graphql language format
*/
public static String printAst(Node node) {
StringWriter sw = new StringWriter();
printAst(sw, node);
return sw.toString();
}
/**
* This will pretty print the AST node in graphql language format
*
* @param writer the place to put the output
* @param node the AST node to print
*/
public static void printAst(Writer writer, Node node) {
printImpl(writer, node, false);
}
/**
* This will print the Ast node in graphql language format in a compact manner, with no new lines
* and comments stripped out of the text.
*
* @param node the AST node to print
*
* @return the printed node in a compact graphql language format
*/
public static String printAstCompact(Node node) {
StringWriter sw = new StringWriter();
printImpl(sw, node, true);
return sw.toString();
}
private static void printImpl(Writer writer, Node node, boolean compactMode) {
AstPrinter astPrinter = new AstPrinter(compactMode);
NodePrinter printer = astPrinter._findPrinter(node);
printer.print(new PrintWriter(writer), node);
}
/**
* These print nodes into output writers
*
* @param the type of node
*/
private interface NodePrinter {
void print(PrintWriter out, T node);
}
}
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