added comments and rustdoc

Dockerfile

@@ -0,0 +1,11 @@
+FROM rust:1.88-alpine as builder
+WORKDIR /usr/src/undeepend
+COPY . .
+RUN cargo install --path .
+
+FROM debian:bullseye-slim
+RUN apt-get update && rm -rf /var/lib/apt/lists/*
+COPY --from=builder /usr/local/cargo/bin/undeepend /usr/local/bin/undeepend
+CMD ["undeepend"]
+
+#&& apt-get install -y extra-runtime-dependencies

README.md

@@ -1,10 +1,15 @@
 currently implementing in rust: 
-* a sax parser to read xml files (and existing xml binding in rust has trouble reading maven properties)
-* a dom parser to get a generic xml representation
-* a pom reader to get a maven specific representation 
-* to find out what dependencies you have
+* V a sax parser to read xml files (and existing xml binding in rust has trouble reading maven properties)
+* V a dom parser to get a generic xml representation
+* V a pom reader to get a maven specific representation 
+* V to find out what dependencies you have
+* try default localRepository ~/.m2/repository
+* load settings.xml
+* search dependency in localRepository
+* download dependency from remote repo's
 
 Why rust and not a maven plugin?
 * faster
 * more challenges
-* run it in docker as a separate step
+* run it in docker as a separate step
+

TODO.md

@@ -0,0 +1,10 @@
+```sh
+docker build -t ghcr.io/shautvast/undeepend:latest .
+docker push ghcr.io/shautvast/undeepend:latest
+```
+
+```sh
+#!/bin/bash
+# undeepend.sh
+docker run --rm -v $(pwd):/project ghcr.io/shautvast/undeepend "$@"
+```

src/main.rs

@@ -1,7 +1,12 @@
-use std::path::Path;
+use std::env;
+use std::path::PathBuf;
 use undeepend::maven::project::parse_project;
 
 fn main() {
-    let project = parse_project(Path::new("tests/maven/resources/sample_project")).unwrap();
+    let args = std::env::args().collect::<Vec<String>>();
+    let dir = if args.len() ==1 {
+        env::current_dir().expect("Could not access current directory")
+    } else { PathBuf::from(&args[1]) };
+    let project = parse_project(&dir).unwrap();
     println!("{:?}", project.get_dependencies(&project.root));
 }

src/maven/metadata.rs

@@ -1,3 +1,6 @@
+// part of maven model, I may throw it away
+
+
 /// The Maven variant to parse poms
 /// These structs is directly modelled after the XML because that is what strong-xml plugin requires
 #[derive(PartialEq, Debug)]

src/maven/mod.rs

@@ -1,5 +1,4 @@
 pub mod metadata;
 pub mod pom;
-pub mod pom_view;
 pub mod pom_parser;
 pub mod project;

src/maven/pom.rs

@@ -1,8 +1,8 @@
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
 
-/// The Maven variant to parse poms
-/// These structs is directly modelled after the XML because that is what strong-xml plugin requires
+/// the maven object model
+
 #[derive(PartialEq, Debug)]
 pub struct Pom {
     pub parent: Option<Parent>,

src/maven/pom_parser.rs

@@ -4,6 +4,7 @@ use crate::xml::dom_parser::{Node, get_document};
 use std::collections::HashMap;
 use std::path::PathBuf;
 
+/// parse the pom.xml into a Pom object (struct)
 pub fn get_pom(xml: impl Into<String>) -> Result<Pom, SaxError> {
     let mut group_id = None;
     let mut artefact_id = None;
@@ -14,7 +15,7 @@ pub fn get_pom(xml: impl Into<String>) -> Result<Pom, SaxError> {
     let mut url = None;
     let mut dependencies = vec![];
     let mut dependency_management = vec![];
-    let mut properties = HashMap::new(); // useless assignment...
+    let mut properties = HashMap::new(); // useless assignments...
     let mut module_names = vec![]; // not useless assignment...
 
     for child in get_document(xml.into().as_str())?.root.children {

src/maven/pom_view.rs

@@ -1,26 +0,0 @@
-/// offers a (non-mutable) view on the pom-as-xml-representation
-/// the main use of this is that it resolves the parent information when needed
-///
-
-#[derive(Debug)]
-pub struct Artifact {
-    pub group: String,
-    pub name: String,
-    pub version: String,
-    pub path: String,
-}
-
-impl Artifact {
-    pub fn new(group: &str, name: &str, version: &str) -> Self {
-        Self {
-            group: group.into(),
-            name: name.into(),
-            version: version.into(),
-            path: format!("{}/{}/{}", group.replace(".", "/"), name, version),
-        }
-    }
-
-    pub fn is_snapshot(&self) -> bool {
-        self.version.ends_with("-SNAPSHOT")
-    }
-}

src/maven/project.rs

@@ -7,6 +7,10 @@ use std::sync::LazyLock;
 
 static PROPERTY_EXPR: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"\$\{(.+)}").unwrap());
 
+/// Loads all poms from a given project directory.
+/// A POM (project object model) is a description of the project to build written in XML.
+/// It has modules which are also a pom.xml in a subdirectory of the project root
+/// (nesting is in theory infinite, but in practice you'll have 2 or maybe 3 levels)
 pub fn parse_project(project_dir: &Path) -> Result<Project, String> {
     if !project_dir.is_dir() {
         return Err(format!("{:?} is not a directory", project_dir));
@@ -14,7 +18,10 @@ pub fn parse_project(project_dir: &Path) -> Result<Project, String> {
 
     let mut pom_file = project_dir.to_path_buf();
     pom_file.push(Path::new("pom.xml"));
-
+    if !pom_file.exists(){
+        return Err(format!("Directory {} does not contain pom.xml", project_dir.to_str().unwrap()));
+    }
+    
     let pom_file = fs::read_to_string(pom_file).map_err(|e| e.to_string())?;
     let mut root = get_pom(pom_file).map_err(|e| e.to_string())?;
 
@@ -22,6 +29,7 @@ pub fn parse_project(project_dir: &Path) -> Result<Project, String> {
     Ok(Project { root })
 }
 
+// examines modules in pom and loads them
 fn resolve_modules(project_dir: &Path, pom: &mut Pom) {
     let mut modules = pom
         .module_names
@@ -34,6 +42,7 @@ fn resolve_modules(project_dir: &Path, pom: &mut Pom) {
     pom.modules.append(&mut modules);
 }
 
+// loads module pom
 fn read_module_pom(project_dir: &Path, module: &String) -> Pom {
     let mut module_dir = project_dir.to_path_buf();
     module_dir.push(Path::new(module));
@@ -48,12 +57,15 @@ fn read_module_pom(project_dir: &Path, module: &String) -> Pom {
     pom
 }
 
+//main entry to project
+//the (root) pom holds the child references to modules
 #[derive(Debug)]
 pub struct Project {
     pub root: Pom,
 }
 
 impl Project {
+    /// get a list of dependencies for a pom in the project
     pub fn get_dependencies(&self, pom: &Pom) -> Vec<Dependency> {
         pom.dependencies
             .iter()
@@ -68,20 +80,31 @@ impl Project {
             .collect()
     }
 
+    // determining a version of a dependency can be done in different ways
+    // 1. version element below dependency, containing the version
+    // 2. version element below dependency, containing a property name that is declared in the pom, or a parent which contains the version
+    // 3. there is no version. In that case in the pom hierarchy there must be a dependencyManagement element in which the version is set
+    // 4. combination of 2 and 3. This is what I typically see in enterprise software. The root pom contains a list of version properties, so all versions are kept in the same place. Takes some diligence to maintain though.
     fn get_version(&self, pom: &Pom, group_id: &str, artifact_id: &str) -> Option<String> {
         pom.dependencies
             .iter()
+            // find to dependency
             .find(|d| d.group_id == group_id && d.artifact_id == artifact_id)
+            // extract the version
             .and_then(|d| d.version.clone())
+            // is it a property?
             .and_then(|version| {
                 if PROPERTY_EXPR.is_match(&version) {
                     let property_name = &PROPERTY_EXPR.captures(&version).unwrap()[1];
+                    // search property in project hierarchy
                     self.get_property(pom, property_name)
                 } else {
                     Some(version)
                 }
             })
             .or_else(|| {
+                // version not set, try dependencyManagement
+                // TODO also search super poms
                 pom.dependency_management
                     .iter()
                     .find(|d| d.group_id == group_id && d.artifact_id == artifact_id)
@@ -97,6 +120,7 @@ impl Project {
             })
     }
 
+    // recursively searches a property going up the chain towards parents
     fn get_property(&self, pom: &Pom, name: &str) -> Option<String> {
         if pom.properties.contains_key(name) {
             pom.properties.get(name).cloned()
@@ -111,7 +135,24 @@ impl Project {
         }
     }
 
+    // look up a pom in the project
     fn get_pom<'a>(&'a self, group_id: &str, artifact_id: &str) -> Option<&'a Pom> {
+
+        // inner function to match poms (by artifactId and groupId)
+        // (extract if needed elsewhere)
+        fn is_same(pom: &Pom, group_id: &str, artifact_id: &str) -> bool {
+            if pom.artifact_id == artifact_id {
+                if let Some(pom_group_id) = &pom.group_id {
+                    pom_group_id == group_id
+                } else {
+                    false
+                }
+            } else {
+                false
+            }
+        }
+
+        // inner function for recursion
         fn get_project_pom<'a>(pom: &'a Pom, group_id: &str, artifact_id: &str) -> Option<&'a Pom> {
             if is_same(pom, group_id, artifact_id) {
                 return Some(pom);
@@ -122,18 +163,8 @@ impl Project {
             }
             None
         }
+
         get_project_pom(&self.root, group_id, artifact_id)
     }
 }
 
-fn is_same(pom: &Pom, group_id: &str, artifact_id: &str) -> bool {
-    if pom.artifact_id == artifact_id {
-        if let Some(pom_group_id) = &pom.group_id {
-            pom_group_id == group_id
-        } else {
-            false
-        }
-    } else {
-        false
-    }
-}

src/xml/debug.rs

@@ -1,35 +0,0 @@
-use log::debug;
-use crate::xml::SaxHandler;
-
-pub struct DebugHandler {}
-
-impl SaxHandler for DebugHandler {
-    fn start_document(&mut self) {
-        debug!("start_document");
-    }
-    fn end_document(&mut self) {
-        debug!("end_document");
-    }
-    fn start_prefix_mapping(&mut self, prefix: &str, _uri: &str) {
-        debug!("start_prefix_mapping for {}", prefix);
-    }
-
-    fn start_element(
-        &mut self,
-        _uri: Option<String>,
-        local_name: &str,
-        _qualified_name: &str,
-        attributes: Vec<crate::xml::Attribute>,
-    ) {
-        debug!("start_element {}, {:?}", local_name, attributes);
-    }
-    fn end_element(&mut self, _uri: Option<String>, local_name: &str, _qualified_name: &str) {
-        debug!("end_element {} ", local_name);
-    }
-    fn characters(&mut self, chars: &[char]) {
-        debug!("characters {:?}", chars.iter().collect::<String>());
-    }
-    fn error(&mut self, _error: &str) {
-        debug!("error");
-    }
-}

src/xml/dom_parser.rs

@@ -1,6 +1,7 @@
 use crate::xml::sax_parser::parse_string;
 use crate::xml::{Attribute, SaxError, SaxHandler};
 
+/// get a generic XML object (Document) from the xml contents. This is called DOM parsing
 pub fn get_document(xml: &str) -> Result<Document, SaxError> {
     let mut dom_hax_handler = DomSaxHandler::new();
     parse_string(xml, Box::new(&mut dom_hax_handler))?;
@@ -13,6 +14,9 @@ pub struct Document {
     pub root: Node,
 }
 
+// used internally to holds usize references to children.
+// needed to ward off the borrow checker
+// don't ask about the name.
 #[derive(Debug, Clone, PartialEq)]
 struct BNode {
     name: String,
@@ -22,6 +26,7 @@ struct BNode {
     text: Option<String>,
 }
 
+// in the end the usize references are translated to other Nodes
 #[derive(Debug, Clone, PartialEq)]
 pub struct Node {
     pub name: String,
@@ -32,13 +37,13 @@ pub struct Node {
 }
 
 impl From<&BNode> for Node {
-    fn from(bnode: &BNode) -> Self {
+    fn from(b_node: &BNode) -> Self {
         Self {
-            name: bnode.name.clone(),
-            namespace: bnode.namespace.clone(),
+            name: b_node.name.clone(),
+            namespace: b_node.namespace.clone(),
             children: vec![],
-            attributes: bnode.attributes.to_vec(),
-            text: bnode.text.clone(),
+            attributes: b_node.attributes.to_vec(),
+            text: b_node.text.clone(),
         }
     }
 }
@@ -58,7 +63,6 @@ impl BNode {
 struct DomSaxHandler {
     node_stack: Vec<usize>,
     nodes: Vec<BNode>,
-    name: String,
 }
 
 impl DomSaxHandler {
@@ -66,19 +70,18 @@ impl DomSaxHandler {
         Self {
             node_stack: vec![],
             nodes: vec![],
-            name: "koe".to_string(),
         }
     }
 
     fn into_doc(self) -> Document {
-        let bnode = &self.nodes[self.node_stack[0]];
-        let node = self.to_node(bnode);
+        let b_node = &self.nodes[self.node_stack[0]];
+        let node = self.to_node(b_node);
         Document { root: node }
     }
 
-    fn to_node(&self, bnode: &BNode) -> Node {
-        let mut node: Node = bnode.into();
-        for child_index in &bnode.children {
+    fn to_node(&self, b_node: &BNode) -> Node {
+        let mut node: Node = b_node.into();
+        for child_index in &b_node.children {
             let child = self.nodes.get(*child_index).unwrap();
             node.children.push(self.to_node(child));
         }

src/xml/mod.rs

@@ -1,5 +1,4 @@
 pub mod sax_parser;
-mod debug;
 pub mod dom_parser;
 
 #[derive(Debug,Clone,PartialEq)]
@@ -9,15 +8,6 @@ pub struct Attribute {
     pub value: String,
 }
 
-enum SaxEvent{
-    StartDocument,
-    EndDocument,
-    StartElement(Option<String>, String, String, Vec<Attribute>),
-    EndElement(Option<String>, String),
-    Characters(String),
-    Error(String)
-}
-
 pub trait SaxHandler {
     fn start_document(&mut self);
     fn end_document(&mut self);
@@ -36,6 +26,8 @@ pub trait SaxHandler {
 
 use std::fmt;
 
+/// Custom error for XML situations
+// likely incomplete
 #[derive(Debug, PartialEq)]
 pub enum SaxError {
     BadCharacter,

src/xml/sax_parser.rs

@@ -1,11 +1,24 @@
 use crate::xml::{Attribute, SaxError, SaxHandler};
 use std::collections::HashMap;
 
+// So I decided to model it after java SAX api, which was a bad choice
+// it defines a trait, like the java SAXHandler interface
+// The rusty way to do it would be using a SAXEvent enum with different variants where there are now trait methods.
+// That would also imply that you go from push (current) to a pull parser, which gives you more control. But hey, who needs that?
+
+/// Parses an xml as string and call the SAXHandler functions accordingly
+// no streaming? Nah. I could do that, but I didn't feel the need, because maven pom.xmls should not be of gigbabyte size
+// It's not a lot of code, but it handles my pom files well, so far. I have see implementations (xml_oxide) that are way bigger.
+// It's a basic recursive descent parser.
+// It handles namespaces (and prefixes) correctly AFAIK
+// No validation (DTD/XSD)
+// I probably missed some other XML functionality that I don't think I need.
 pub fn parse_string(xml: &str, handler: Box<&mut dyn SaxHandler>) -> Result<(), SaxError> {
     SAXParser::new(xml, handler).parse()
 }
 
-pub struct SAXParser<'a> {
+// struct containing the parser state
+struct SAXParser<'a> {
     xml: Vec<char>,
     handler: Box<&'a mut dyn SaxHandler>,
     position: usize,
@@ -16,7 +29,8 @@ pub struct SAXParser<'a> {
 }
 
 impl<'a> SAXParser<'a> {
-    pub fn new(xml: &str, handler: Box<&'a mut dyn SaxHandler>) -> Self {
+    ///
+    fn new(xml: &str, handler: Box<&'a mut dyn SaxHandler>) -> Self {
         Self {
             xml: xml.chars().collect(),
             handler,