feat(spxls): add support for retrieving package documentation in hover

tools/spxls/internal/server/compile.go

@@ -8,6 +8,7 @@ import (
 	"maps"
 	"path"
 	"slices"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -510,6 +511,42 @@ func (r *compileResult) spxResourceRefAtASTFilePosition(astFile *gopast.File, po
 	return bestRef
 }
 
+// spxImportsAtASTFilePosition returns the import at the given position in the given AST file.
+func (r *compileResult) spxImportsAtASTFilePosition(astFile *gopast.File, position Position) *SpxReferencePkg {
+	spxFile := r.nodeFilename(astFile)
+	line := int(position.Line) + 1
+	column := int(position.Character) + 1
+
+	var rpkg *SpxReferencePkg
+
+	for _, imp := range astFile.Imports {
+		nodePos := r.fset.Position(imp.Pos())
+		nodeEnd := r.fset.Position(imp.End())
+		if nodePos.Filename != spxFile ||
+			line != nodePos.Line ||
+			column < nodePos.Column ||
+			column > nodeEnd.Column {
+			continue
+		}
+
+		pkg := imp.Path.Value
+		unquoted, err := strconv.Unquote(pkg)
+		if err != nil {
+			continue
+		}
+		pkgDoc, err := pkgdata.GetPkgDoc(unquoted)
+		if err == nil {
+			rpkg = &SpxReferencePkg{
+				Pkg:     pkgDoc,
+				PkgPath: pkg,
+				Node:    imp,
+			}
+		}
+
+	}
+	return rpkg
+}
+
 // addSpxResourceRef adds an spx resource reference to the compile result.
 func (r *compileResult) addSpxResourceRef(ref SpxResourceRef) {
 	if r.seenSpxResourceRefs == nil {

tools/spxls/internal/server/hover.go

@@ -1,6 +1,9 @@
 package server
 
-import "strings"
+import (
+	"go/doc"
+	"strings"
+)
 
 // See https://microsoft.github.io/language-server-protocol/specifications/lsp/3.18/specification#textDocument_hover
 func (s *Server) textDocumentHover(params *HoverParams) (*Hover, error) {
@@ -22,6 +25,19 @@ func (s *Server) textDocumentHover(params *HoverParams) (*Hover, error) {
 		}, nil
 	}
 
+	// Check if the position is within an import declaration.
+	// If so, return the package documentation.
+	rpkg := result.spxImportsAtASTFilePosition(astFile, params.Position)
+	if rpkg != nil {
+		return &Hover{
+			Contents: MarkupContent{
+				Kind:  Markdown,
+				Value: doc.Synopsis(rpkg.Pkg.Doc),
+			},
+			Range: result.rangeForNode(rpkg.Node),
+		}, nil
+	}
+
 	ident := result.identAtASTFilePosition(astFile, params.Position)
 	if ident == nil {
 		return nil, nil

tools/spxls/internal/server/spx_reference_pkg.go

@@ -0,0 +1,13 @@
+package server
+
+import (
+	"github.com/goplus/builder/tools/spxls/internal/pkgdoc"
+	gopast "github.com/goplus/gop/ast"
+)
+
+// SpxReferencePkg is a reference to an imported package.
+type SpxReferencePkg struct {
+	PkgPath string
+	Pkg     *pkgdoc.PkgDoc
+	Node    *gopast.ImportSpec
+}