pmd/docs/_data/xpath_funs.yml

# This file describes custom XPath functions per language
# This is rendered using _includes/custom/xpath_fun_doc.html

aliases:
  - &qname_param
    name: javaQualifiedName
    type: "xs:string"
    description: "The qualified name of a Java class, possibly with pairs of brackets to indicate an array type.
                  Can also be a primitive type name."
  - &node_param
    name: element
    type: "xs:element"
    description: "Any element node"
  - &needs_typenode "The context node must be a {% jdoc jast::TypeNode %}"
  - &coord_fun_note |
      The function is not context-dependent, but takes a node as its first parameter.
  - &needs_node_ctx "The requires the context node to be an element"

langs:
  - name: "All languages"
    ns: "pmd"
    header: "Functions available to all languages are in the namespace `pmd`."
    funs:
      - name: fileName
        returnType: "xs:string"
        shortDescription: "Returns the simple name of the current file"
        description: |
          Returns the current simple file name, without path but including the extension.
          This can be used to write rules that check file naming conventions.

        since: 6.38.0
        notes: *needs_node_ctx
        examples:
          - code: "//b[pmd:fileName() = 'Foo.xml']"
            outcome: "Matches any `<b>` tags in files called `Foo.xml`."

      - name: startLine
        returnType: "xs:int"
        parameters:
          - *node_param
        shortDescription: "Returns the start line of the given node"
        description: |
          Returns the line where the node starts in the source file.
          Line numbers are 1-based.

        since: 6.44.0
        notes: *coord_fun_note
        examples:
          - code: "//b[pmd:startLine(.) > 5]"
            outcome: "Matches any `<b>` node which starts after the fifth line."

      - name: endLine
        returnType: "xs:int"
        parameters:
          - *node_param
        shortDescription: "Returns the end line of the given node"
        description: |
          Returns the line where the node ends in the source file.
          Line numbers are 1-based.

        since: 6.44.0
        notes: *coord_fun_note
        examples:
          - code: "//b[pmd:endLine(.) == pmd:startLine(.)]"
            outcome: "Matches any `<b>` node which doesn't span more than one line."

      - name: startColumn
        returnType: "xs:int"
        parameters:
          - *node_param
        shortDescription: "Returns the start column of the given node (inclusive)"
        description: |
          Returns the column number where the node starts in the source file.
          Column numbers are 1-based. The start column is inclusive.

        since: 6.44.0
        notes: *coord_fun_note
        examples:
          - code: "//b[pmd:startColumn(.) = 1]"
            outcome: "Matches any `<b>` node which starts on the first column of a line"

      - name: endColumn
        returnType: "xs:int"
        parameters:
          - *node_param
        shortDescription: "Returns the end column of the given node (exclusive)"
        description: |
          Returns the column number where the node ends in the source file.
          Column numbers are 1-based. The end column is exclusive.

        since: 6.44.0
        notes: *coord_fun_note
        examples:
          - code: "//b[pmd:startLine(.) = pmd:endLine(.) and pmd:endColumn(.) - pmd:startColumn(.) = 1]"
            outcome: "Matches any `<b>` node which spans exactly one character"

  - name: "Java"
    ns: "pmd-java"
    funs:
      - name: nodeIs
        returnType: "xs:boolean"
        shortDescription: "Tests the runtime type of the node instance"
        description: "Returns true if the runtime type of the AST node is a subtype of the given class.
                      Contrary to typeIs, this tests the type of the AST node.
                      For example, the AST node for a literal (e.g. `5d`) has type ASTNumericLiteral,
                      and this function will ignore the static type of the expression (double)"
        parameters:
          - name: nodeClassName
            type: "xs:string"
            description: "Simple name of a class or interface in package {% jdoc_package :jast %}, without the 'AST' prefix"
        examples:
          - code: '//*[pmd-java:nodeIs("Expression")]'
            outcome: "Matches all nodes that implement {% jdoc jast::ASTExpression %}"
          - code: '//*[pmd-java:nodeIs("AnyTypeDeclaration")]'
            outcome: "Matches all nodes that implement {% jdoc jast::ASTAnyTypeDeclaration %}"
          - code: '//*[pmd-java:nodeIs("Foo")]'
            outcome: "Runtime error, there's no class ASTFoo in the package"

      - name: typeIs
        returnType: "xs:boolean"
        shortDescription: "Tests a node's static type"
        description: "Returns true if the context node's static Java type is a subtype of the given type.
                      This tests for the resolved type of the Java construct, not the type of the AST node.
                      For example, the AST node for a literal (e.g. `5d`) has type ASTNumericLiteral, however this
                      function will compare the type of the literal (eg here, `double`) against the argument."
        notes: *needs_typenode
        parameters:
          - *qname_param
        examples:
          - code: '//FormalParameter[pmd-java:typeIs("java.lang.String[]")]'
            outcome: "Matches formal parameters of type `String[]` (including vararg parameters)"
          - code: '//VariableDeclaratorId[pmd-java:typeIs("java.lang.List")]'
            outcome: "Matches variable declarators of type `List` or any of its subtypes (including e.g. `ArrayList`)"

      - name: typeIsExactly
        returnType: "xs:boolean"
        shortDescription: "Tests a node's static type, ignoring subtypes"
        description: "Returns true if the context node's static type is exactly the given type.
                      In particular, returns false if the context node's type is
                      a subtype of the given type."
        notes: *needs_typenode
        parameters:
          - *qname_param
        examples:
          - code: '//VariableDeclaratorId[pmd-java:typeIsExactly("java.lang.List")]'
            outcome: "Matches variable declarators of type `List` (but not e.g. `ArrayList`)"


      - name: metric
        returnType: "xs:decimal?"
        shortDescription: "Computes and returns the value of a metric"
        description:
          Returns the value of the metric as evaluated on the context node.
          If the metric cannot be computed on that node, returns an empty sequence
          (which is falsy).

        parameters:
          - name: "metricKey"
            type: "xs:string"
            description: "The name of a metric in {% jdoc jmx::JavaMetrics %} (or an alias thereof)."
        examples:
          - code: "//ClassOrInterfaceDeclaration[metric('NCSS') > 200]"
            outcome: ""
          - code: "//MethodDeclaration[metric('CYCLO') > 10 and metric('NCSS') > 20]"
            outcome: ""
          - code: "//TypeParameter[metric('idontexist') > 50]"
            outcome: "Error: no such metric"

      - name: hasAnnotation
        returnType: "xs:boolean"
        shortDescription: "Tests whether an annotation is present on the node"
        description: "Returns true if the node has an annotation with the given qualified name"
        notes: "The context node must be an {% jdoc jast::Annotatable %}, otherwise this returns false"
        parameters:
          - name: annotationClassName
            type: "xs:string"
            description: "Canonical name of an annotation type"
        examples:
          - code: '//MethodDeclaration[pmd-java:hasAnnotation("java.lang.Override")]'
            outcome: "Matches all method declarations that are annotated with @Override"

      - name: modifiers
        returnType: "xs:string*"
        shortDescription: "Produce the effective modifiers of a node"
        description: >-
          Returns a sequence of the effective modifiers of a node as strings.
          This is documented on {% jdoc jast::ASTModifierList#getEffectiveModifiers() %}.

        notes: "The context node must be an {% jdoc jast::AccessNode %}, otherwise this returns an empty sequence"
        parameters:
        examples:
          - code: '//MethodDeclaration[pmd-java:modifiers() = "native"]'
            outcome: "Matches native method declarations"
          - code: '//MethodDeclaration[pmd-java:modifiers() = ("native", "static")]'
            outcome: >-
              Matches method declarations that have a 'native' OR a 'static' modifier.
              This may be counter-intuitive.
          - code: '//MethodDeclaration[pmd-java:modifiers() = "public"]'
            outcome: >-
              Matches method declarations that have a 'public' modifier, explicit or implicit.
              For example, this would match methods in interfaces, which implicitly have the
              modifier. Use the `explicitModifiers` function if you don't want the implicit part.
              Also note that `@Visibility = 'public'` is a better use of the API, in this particular
              instance.

      - name: explicitModifiers
        returnType: "xs:string*"
        shortDescription: "Produce the explicit modifiers of a node"
        description: >-
          Returns a sequence of the explicit modifiers of a node as strings.
          This is documented on {% jdoc jast::ASTModifierList#getExplicitModifiers() %}.

        notes: "The context node must be an {% jdoc jast::AccessNode %}, otherwise this returns an empty sequence"
        parameters:
        examples:
          - code: '//MethodDeclaration[pmd-java:explicitModifiers() = "public"]'
            outcome: "Matches method declarations that have an explicit 'public' modifier."

      - name: matchesSig
        returnType: "xs:boolean"
        shortDescription: "Matches the signature called by a method or constructor call"
        description: >-
          Uses an {% jdoc java::lang.java.types.TypeTestUtil.InvocationMatcher %} to test
          the method signature called by the context node. The format of the parameter is
          described on that class.

        notes: "The context node must be an {% jdoc jast::InvocationNode %}, otherwise this returns false"
        parameters:
          - name: "sig"
            type: "xs:string"
            description: "A signature, in the format described on {% jdoc java::lang.java.types.TypeTestUtil.InvocationMatcher %}"
        examples:
          - code: '//MethodCall[pmd-java:matchesSig("_#equals(java.lang.Object)")]'
            outcome: "Matches calls to the method `equals` on any receiver type"
          - code: '//MethodCall[pmd-java:matchesSig("java.lang.Enum#equals(java.lang.Object)")]'
            outcome: "Matches calls to the method `equals` on receiver that is a subtype of Enum"
          - code: '//MethodCall[pmd-java:matchesSig("java.lang.String#toString()")]'
            outcome: "Matches calls to the method `toString` on String receivers"
          - code: '//MethodCall[pmd-java:matchesSig("_#_(int,int)")]'
            outcome: "Matches calls to any method with 2 `int` parameters (!= argument)"
          - code: '//ConstructorCall[pmd-java:matchesSig("java.util.ArrayList#new(int)")]'
            outcome: "Matches constructors calls of ArrayList with a single int parameter"