feat(solc): add tree printer implementation (#933)

* feat(solc): add tree printer implementation

* test: feature gate windows

* typos

ethers-solc/src/lib.rs

@@ -9,7 +9,7 @@ pub mod cache;
 pub mod hh;
 pub use artifact_output::*;
 
-mod resolver;
+pub mod resolver;
 pub use hh::{HardhatArtifact, HardhatArtifacts};
 pub use resolver::Graph;
 

ethers-solc/src/resolver/mod.rs

@@ -48,6 +48,7 @@
 
 use std::{
     collections::{HashMap, HashSet, VecDeque},
+    fmt, io,
     path::{Path, PathBuf},
 };
 
@@ -58,6 +59,9 @@ use solang_parser::pt::{Import, Loc, SourceUnitPart};
 
 use crate::{error::Result, utils, ProjectPathsConfig, Solc, SolcError, Source, Sources};
 
+mod tree;
+pub use tree::{print, Charset, TreeOptions};
+
 /// The underlying edges of the graph which only contains the raw relationship data.
 ///
 /// This is kept separate from the `Graph` as the `Node`s get consumed when the `Solc` to `Sources`
@@ -129,11 +133,28 @@ pub struct Graph {
 }
 
 impl Graph {
+    /// Print the graph to `StdOut`
+    pub fn print(&self) {
+        self.print_with_options(Default::default())
+    }
+
+    /// Print the graph to `StdOut` using the provided `TreeOptions`
+    pub fn print_with_options(&self, opts: TreeOptions) {
+        let stdout = io::stdout();
+        let mut out = stdout.lock();
+        tree::print(self, &opts, &mut out).expect("failed to write to stdout.")
+    }
+
     /// Returns a list of nodes the given node index points to for the given kind.
     pub fn imported_nodes(&self, from: usize) -> &[usize] {
         self.edges.imported_nodes(from)
     }
 
+    /// Returns `true` if the given node has any outgoing edges.
+    pub(crate) fn has_outgoing_edges(&self, index: usize) -> bool {
+        !self.edges.edges[index].is_empty()
+    }
+
     /// Returns all the resolved files and their index in the graph
     pub fn files(&self) -> &HashMap<PathBuf, usize> {
         &self.edges.indices
@@ -148,6 +169,9 @@ impl Graph {
         &self.nodes[index]
     }
 
+    pub(crate) fn display_node(&self, index: usize) -> DisplayNode {
+        DisplayNode { node: self.node(index), root: &self.root }
+    }
     /// Returns an iterator that yields all nodes of the dependency tree that the given node id
     /// spans, starting with the node itself.
     ///
@@ -646,6 +670,23 @@ impl Node {
     }
 }
 
+/// Helper type for formatting a node
+pub(crate) struct DisplayNode<'a> {
+    node: &'a Node,
+    root: &'a PathBuf,
+}
+
+impl<'a> fmt::Display for DisplayNode<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let path = utils::source_name(&self.node.path, self.root);
+        write!(f, "{}", path.display())?;
+        if let Some(ref v) = self.node.data.version {
+            write!(f, " {}", v.data())?;
+        }
+        Ok(())
+    }
+}
+
 #[derive(Debug, Clone)]
 #[allow(unused)]
 struct SolData {
@@ -850,4 +891,47 @@ mod tests {
         );
         assert_eq!(graph.imported_nodes(1).to_vec(), vec![2, 0]);
     }
+
+    #[test]
+    #[cfg(not(target_os = "windows"))]
+    fn can_print_dapp_sample_graph() {
+        let root = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("test-data/dapp-sample");
+        let paths = ProjectPathsConfig::dapptools(root).unwrap();
+        let graph = Graph::resolve(&paths).unwrap();
+        let mut out = Vec::<u8>::new();
+        tree::print(&graph, &Default::default(), &mut out).unwrap();
+
+        assert_eq!(
+            "
+src/Dapp.sol >=0.6.6
+src/Dapp.t.sol >=0.6.6
+├── lib/ds-test/src/test.sol >=0.4.23
+└── src/Dapp.sol >=0.6.6
+"
+            .trim_start()
+            .as_bytes()
+            .to_vec(),
+            out
+        );
+    }
+
+    #[test]
+    #[cfg(not(target_os = "windows"))]
+    fn can_print_hardhat_sample_graph() {
+        let root = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("test-data/hardhat-sample");
+        let paths = ProjectPathsConfig::hardhat(root).unwrap();
+        let graph = Graph::resolve(&paths).unwrap();
+        let mut out = Vec::<u8>::new();
+        tree::print(&graph, &Default::default(), &mut out).unwrap();
+        assert_eq!(
+            "
+contracts/Greeter.sol >=0.6.0
+└── node_modules/hardhat/console.sol >= 0.4.22 <0.9.0
+"
+            .trim_start()
+            .as_bytes()
+            .to_vec(),
+            out
+        );
+    }
 }

ethers-solc/src/resolver/tree.rs

@@ -0,0 +1,183 @@
+use crate::Graph;
+use std::{collections::HashSet, io, io::Write, str::FromStr};
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+pub enum Charset {
+    Utf8,
+    Ascii,
+}
+
+impl Default for Charset {
+    fn default() -> Self {
+        // when operating in a console on windows non-UTF-8 byte sequences are not supported on
+        // stdout, See also [`StdoutLock`]
+        #[cfg(target_os = "windows")]
+        {
+            Charset::Ascii
+        }
+        #[cfg(not(target_os = "windows"))]
+        Charset::Utf8
+    }
+}
+
+impl FromStr for Charset {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "utf8" => Ok(Charset::Utf8),
+            "ascii" => Ok(Charset::Ascii),
+            s => Err(format!("invalid charset: {}", s)),
+        }
+    }
+}
+
+/// Options to configure formatting
+#[derive(Debug, Clone, Default)]
+pub struct TreeOptions {
+    /// The style of characters to use.
+    pub charset: Charset,
+    /// If `true`, duplicate imports will be repeated.
+    /// If `false`, duplicates are suffixed with `(*)`, and their imports
+    /// won't be shown.
+    pub no_dedupe: bool,
+}
+
+/// Internal helper type for symbols
+struct Symbols {
+    down: &'static str,
+    tee: &'static str,
+    ell: &'static str,
+    right: &'static str,
+}
+
+static UTF8_SYMBOLS: Symbols = Symbols { down: "│", tee: "├", ell: "└", right: "─" };
+
+static ASCII_SYMBOLS: Symbols = Symbols { down: "|", tee: "|", ell: "`", right: "-" };
+
+pub fn print(graph: &Graph, opts: &TreeOptions, out: &mut dyn Write) -> io::Result<()> {
+    let symbols = match opts.charset {
+        Charset::Utf8 => &UTF8_SYMBOLS,
+        Charset::Ascii => &ASCII_SYMBOLS,
+    };
+
+    // used to determine whether to display `(*)`
+    let mut visited_imports = HashSet::new();
+
+    // A stack of bools used to determine where | symbols should appear
+    // when printing a line.
+    let mut levels_continue = Vec::new();
+    // used to detect dependency cycles when --no-dedupe is used.
+    // contains a `Node` for each level.
+    let mut write_stack = Vec::new();
+
+    for (node_index, _) in graph.input_nodes().enumerate() {
+        print_node(
+            graph,
+            node_index,
+            symbols,
+            opts.no_dedupe,
+            &mut visited_imports,
+            &mut levels_continue,
+            &mut write_stack,
+            out,
+        )?;
+    }
+
+    Ok(())
+}
+
+#[allow(clippy::too_many_arguments)]
+fn print_node(
+    graph: &Graph,
+    node_index: usize,
+    symbols: &Symbols,
+    no_dedupe: bool,
+    visited_imports: &mut HashSet<usize>,
+    levels_continue: &mut Vec<bool>,
+    write_stack: &mut Vec<usize>,
+    out: &mut dyn Write,
+) -> io::Result<()> {
+    let new_node = no_dedupe || visited_imports.insert(node_index);
+
+    if let Some((last_continues, rest)) = levels_continue.split_last() {
+        for continues in rest {
+            let c = if *continues { symbols.down } else { " " };
+            write!(out, "{}   ", c)?;
+        }
+
+        let c = if *last_continues { symbols.tee } else { symbols.ell };
+        write!(out, "{0}{1}{1} ", c, symbols.right)?;
+    }
+
+    let in_cycle = write_stack.contains(&node_index);
+    // if this node does not have any outgoing edges, don't include the (*)
+    // since there isn't really anything "deduplicated", and it generally just
+    // adds noise.
+    let has_deps = graph.has_outgoing_edges(node_index);
+    let star = if (new_node && !in_cycle) || !has_deps { "" } else { " (*)" };
+
+    writeln!(out, "{}{}", graph.display_node(node_index), star)?;
+
+    if !new_node || in_cycle {
+        return Ok(())
+    }
+    write_stack.push(node_index);
+
+    print_imports(
+        graph,
+        node_index,
+        symbols,
+        no_dedupe,
+        visited_imports,
+        levels_continue,
+        write_stack,
+        out,
+    )?;
+
+    write_stack.pop();
+
+    Ok(())
+}
+
+/// Prints all the imports of a node
+#[allow(clippy::too_many_arguments, clippy::ptr_arg)]
+fn print_imports(
+    graph: &Graph,
+    node_index: usize,
+    symbols: &Symbols,
+    no_dedupe: bool,
+    visited_imports: &mut HashSet<usize>,
+    levels_continue: &mut Vec<bool>,
+    write_stack: &mut Vec<usize>,
+    out: &mut dyn Write,
+) -> io::Result<()> {
+    let imports = graph.imported_nodes(node_index);
+    if imports.is_empty() {
+        return Ok(())
+    }
+
+    for continues in &**levels_continue {
+        let c = if *continues { symbols.down } else { " " };
+        write!(out, "{}   ", c)?;
+    }
+
+    let mut iter = imports.iter().peekable();
+
+    while let Some(import) = iter.next() {
+        levels_continue.push(iter.peek().is_some());
+        print_node(
+            graph,
+            *import,
+            symbols,
+            no_dedupe,
+            visited_imports,
+            levels_continue,
+            write_stack,
+            out,
+        )?;
+        levels_continue.pop();
+    }
+
+    Ok(())
+}