Add support for snapshotted Maven artifacts

Artifacts with snapshots follow a different naming scheme than
non-snapshoted ones.  For snapshotted artifacts, the version component
in the URL is the generic *-SNAPSHOT name, whereas the version component
in the file name is the specific version number.

Fixes #901.

Author: jmmv

private/rules/v2_lock_file.bzl

@@ -43,10 +43,13 @@ def _compute_lock_file_hash(lock_file_contents):
     return hash(repr(to_hash))
 
 def _to_m2_path(unpacked):
-    path = "{group}/{artifact}/{version}/{artifact}-{version}".format(
+    version = unpacked["version"]
+    dir_version = getattr(unpacked, "dirVersion", version)
+    path = "{group}/{artifact}/{dir_version}/{artifact}-{version}".format(
         artifact = unpacked["artifactId"],
         group = unpacked["groupId"].replace(".", "/"),
-        version = unpacked["version"],
+        version = version,
+        dir_version = dir_version,
     )
 
     classifier = unpacked.get("scope", "jar")
@@ -104,6 +107,8 @@ def _get_artifacts(lock_file_contents):
             "artifactId": parts[1],
             "version": data["version"],
         }
+        if "dirVersion" in data:
+            root_unpacked["dirVersion"] = data["dirVersion"]
         if len(parts) > 2:
             root_unpacked["type"] = parts[2]
         else:

private/tools/java/com/github/bazelbuild/rules_jvm_external/Coordinates.java

@@ -5,10 +5,15 @@
 /**
  * Represents a Maven coordinate using Maven's standard schema of
  * <groupId>:<artifactId>[:<extension>[:<classifier>][:<version>].
+ *
+ * <p>The optional <tt>dirVersion</tt> property is used for snapshotted artifacts.  For those,
+ * directory version component in the repository URL is of the <tt>*-SNAPSHOT</tt> * form
+ * whereas the version in the artifact itself numeric.</p>
  */
 public class Coordinates implements Comparable<Coordinates> {
   private final String groupId;
   private final String artifactId;
+  private final String dirVersion;
   private final String version;
   private final String classifier;
   private final String extension;
@@ -27,6 +32,7 @@ public Coordinates(String coordinates) {
 
     groupId = Objects.requireNonNull(parts[0]);
     artifactId = Objects.requireNonNull(parts[1]);
+    dirVersion = null;
 
     if (parts.length == 2) {
       extension = "jar";
@@ -48,12 +54,13 @@ public Coordinates(String coordinates) {
   }
 
   public Coordinates(
-      String groupId, String artifactId, String extension, String classifier, String version) {
+      String groupId, String artifactId, String extension, String classifier, String version, String dirVersion) {
     this.groupId = Objects.requireNonNull(groupId, "Group ID");
     this.artifactId = Objects.requireNonNull(artifactId, "Artifact ID");
     this.extension = extension == null || extension.isEmpty() ? "jar" : extension;
     this.classifier = classifier == null || classifier.isEmpty() ? "" : classifier;
     this.version = version == null || version.isEmpty() ? "" : version;
+    this.dirVersion = dirVersion;
   }
 
   public String getGroupId() {
@@ -64,6 +71,10 @@ public String getArtifactId() {
     return artifactId;
   }
 
+  public String getDirVersion() {
+    return dirVersion;
+  }
+
   public String getVersion() {
     return version;
   }
@@ -73,11 +84,13 @@ public String getClassifier() {
   }
 
   public Coordinates setClassifier(String classifier) {
-    return new Coordinates(getGroupId(), getArtifactId(), getExtension(), classifier, getVersion());
+    return new Coordinates(
+        getGroupId(), getArtifactId(), getExtension(), classifier, getVersion(), getDirVersion());
   }
 
   public Coordinates setExtension(String extension) {
-    return new Coordinates(getGroupId(), getArtifactId(), extension, getClassifier(), getVersion());
+    return new Coordinates(
+        getGroupId(), getArtifactId(), extension, getClassifier(), getVersion(), getDirVersion());
   }
 
   public String getExtension() {
@@ -132,6 +145,7 @@ public boolean equals(Object o) {
     Coordinates that = (Coordinates) o;
     return getGroupId().equals(that.getGroupId())
         && getArtifactId().equals(that.getArtifactId())
+        && Objects.equals(getDirVersion(), that.getDirVersion())
         && Objects.equals(getVersion(), that.getVersion())
         && Objects.equals(getClassifier(), that.getClassifier())
         && Objects.equals(getExtension(), that.getExtension());
@@ -140,6 +154,7 @@ && getArtifactId().equals(that.getArtifactId())
   @Override
   public int hashCode() {
     return Objects.hash(
-        getGroupId(), getArtifactId(), getVersion(), getClassifier(), getExtension());
+        getGroupId(), getArtifactId(), getDirVersion(), getVersion(), getClassifier(),
+        getExtension());
   }
 }

private/tools/java/com/github/bazelbuild/rules_jvm_external/coursier/LockFileConverter.java

@@ -256,21 +256,66 @@ private Map<Coordinates, Coordinates> deriveCoordinateMappings(Map<String, Objec
       // After the version, there should be nothing left but a file name
       pathSubstring = pathSubstring.substring(version.length() + 1);
 
-      // Now we know the version, we can calculate the expected file name. For now, ignore
-      // the fact that there may be a classifier. We're going to derive that if necessary.
-      String expectedFileName = coord.getArtifactId() + "-" + version;
+      String remainder;
+      String dirVersion;
+      if (version.endsWith("-SNAPSHOT")) {
+        String baseVersion = version.substring(0, version.length() - "-SNAPSHOT".length());
 
-      index = pathSubstring.indexOf(expectedFileName);
-      if (index == -1) {
-        throw new IllegalArgumentException(
-            String.format(
-                "Expected file name (%s) not found in path (%s). Current coordinates are %s",
-                expectedFileName, file, coord));
+        String expectedFileName = coord.getArtifactId() + "-" + baseVersion + "YYYYMMDD-HHMMSS.N+";
+
+        index = pathSubstring.indexOf(baseVersion);
+        if (index == -1) {
+          throw new IllegalArgumentException(
+              String.format(
+                  "Expected artifact (%s) not found in path (%s). Current coordinates are %s",
+                  expectedFileName, file, coord));
+        }
+        index = index + baseVersion.length();
+        int snapshotVersionStart = index;
+
+        // Skip over the YYYYMMDD part.
+        if (pathSubstring.charAt(index + 9) != '.') {
+          throw new IllegalArgumentException(
+              String.format(
+                  "Expected artifact (%s) not found in path (%s). Current coordinates are %s",
+                  expectedFileName, file, coord));
+        }
+        index = index + 9;
+
+        // Skip over the HHMMSS part.
+        if (pathSubstring.charAt(index + 7) != '-') {
+          throw new IllegalArgumentException(
+              String.format(
+                  "Expected artifact (%s) not found in path (%s). Current coordinates are %s",
+                  expectedFileName, file, coord));
+        }
+        index = index + 7;
+
+        // Skip over the variable-length build number.
+        index = pathSubstring.indexOf(".", index + 1);
+
+        remainder = pathSubstring.substring(index);
+        dirVersion = version;
+        version = baseVersion + pathSubstring.substring(snapshotVersionStart, index);
+      } else {
+        // Now we know the version, we can calculate the expected file name. For now, ignore
+        // the fact that there may be a classifier. We're going to derive that if necessary.
+        String expectedFileName = coord.getArtifactId() + "-" + version;
+
+        index = pathSubstring.indexOf(expectedFileName);
+        if (index == -1) {
+          throw new IllegalArgumentException(
+              String.format(
+                  "Expected file name (%s) not found in path (%s). Current coordinates are %s",
+                  expectedFileName, file, coord));
+        }
+
+        remainder = pathSubstring.substring(expectedFileName.length());
+        dirVersion = null;
       }
 
       String classifier = "";
       String extension = "";
-      String remainder = pathSubstring.substring(expectedFileName.length());
 
       if (remainder.isEmpty()) {
         throw new IllegalArgumentException(
@@ -303,7 +348,7 @@ private Map<Coordinates, Coordinates> deriveCoordinateMappings(Map<String, Objec
       toReturn.put(
           coord,
           new Coordinates(
-              coord.getGroupId(), coord.getArtifactId(), extension, classifier, version));
+              coord.getGroupId(), coord.getArtifactId(), extension, classifier, version, dirVersion));
     }
 
     return toReturn;

private/tools/java/com/github/bazelbuild/rules_jvm_external/coursier/NebulaFormat.java

@@ -57,6 +57,10 @@ public Map<String, Object> render(Set<DependencyInfo> infos, Map<String, Object>
           Map<String, Object> artifactValue =
               artifacts.computeIfAbsent(shortKey, k -> new TreeMap<>());
           artifactValue.put("version", coords.getVersion());
+          String dirVersion = coords.getDirVersion();
+          if (dirVersion != null) {
+            artifactValue.put("dirVersion", coords.getDirVersion());
+          }
 
           String classifier = coords.getClassifier();
           if (classifier == null || classifier.isEmpty()) {