examples UPDATE extension parsing and validation

Author: Ardival

tools/lint/examples/README.md

@@ -18,6 +18,7 @@ Available commands:
   load            Load a new schema from the searchdirs
   print           Print a module
   data            Load, validate and optionally print instance data
+  ext             Validate extension data
   list            List all the loaded modules
   feature         Print all features of module(s) with their state
   searchpath      Print/set the search path(s) for schemas
@@ -534,3 +535,28 @@ $ yanglint -f json -t config -p . -Y sm-context-main.xml -x sm-context-extension
   }
 }
 ```
+
+## Validating extension data
+
+The input data should be parsed and validated strictly according to the schema tree defined by the extension instance.
+
+The tool parses and validates the input file (ext-data.xml) as a standalone extension data tree, not as part of a complete configuration. It does not allow mixing extension data with normal module data.
+
+Preparation:
+
+```
+> clear
+> add [email protected]
+> add example-jukebox.yang
+> data -i -k rc:yang-data:yang-errors ext-data.xml
+```
+
+Output:
+
+```
+libyang[0]: Invalid instance-identifier "/example-jukebox:jukebox/library" value - required instance not found. (data path: /ietf-restconf:errors/error[1]/error-path)
+YANGLINT[E]: Parsing of extension data failed.
+
+```
+This error indicates that the input file refers to data (/example-jukebox:jukebox/library) that do not exist in the extension's schema tree — which violates the rules.
+

tools/lint/examples/example-jukebox.yang

@@ -0,0 +1,239 @@
+module example-jukebox {
+
+   namespace "http://example.com/ns/example-jukebox";
+   prefix "jbox";
+
+   organization "Example, Inc.";
+   contact "support at example.com";
+   description "Example Jukebox Data Model Module";
+   revision "2016-08-15" {
+     description "Initial version.";
+     reference "example.com document 1-4673";
+   }
+
+   identity genre {
+     description "Base for all genre types";
+   }
+
+   // abbreviated list of genre classifications
+   identity alternative {
+     base genre;
+     description "Alternative music";
+   }
+   identity blues {
+     base genre;
+     description "Blues music";
+   }
+   identity country {
+     base genre;
+     description "Country music";
+   }
+   identity jazz {
+     base genre;
+     description "Jazz music";
+   }
+   identity pop {
+     base genre;
+     description "Pop music";
+   }
+   identity rock {
+     base genre;
+     description "Rock music";
+   }
+
+   container jukebox {
+     presence
+       "An empty container indicates that the jukebox
+        service is available";
+
+     description
+       "Represents a jukebox resource, with a library, playlists,
+        and a play operation.";
+
+     container library {
+
+       description "Represents the jukebox library resource.";
+
+       list artist {
+         key name;
+
+         description
+           "Represents one artist resource within the
+            jukebox library resource.";
+
+         leaf name {
+           type string {
+             length "1 .. max";
+           }
+           description "The name of the artist.";
+         }
+
+         list album {
+           key name;
+
+           description
+             "Represents one album resource within one
+              artist resource, within the jukebox library.";
+
+           leaf name {
+             type string {
+               length "1 .. max";
+             }
+             description "The name of the album.";
+           }
+
+           leaf genre {
+             type identityref { base genre; }
+             description
+               "The genre identifying the type of music on
+                the album.";
+           }
+
+           leaf year {
+             type uint16 {
+               range "1900 .. max";
+             }
+             description "The year the album was released";
+           }
+
+           container admin {
+             description
+               "Administrative information for the album.";
+
+             leaf label {
+               type string;
+               description "The label that released the album.";
+             }
+             leaf catalogue-number {
+               type string;
+               description "The album's catalogue number.";
+             }
+           }
+
+           list song {
+             key name;
+
+             description
+               "Represents one song resource within one
+                album resource, within the jukebox library.";
+
+             leaf name {
+               type string {
+                  length "1 .. max";
+               }
+               description "The name of the song";
+             }
+             leaf location {
+               type string;
+               mandatory true;
+               description
+                "The file location string of the
+                 media file for the song";
+             }
+             leaf format {
+               type string;
+               description
+                 "An identifier string for the media type
+                  for the file associated with the
+                  'location' leaf for this entry.";
+             }
+             leaf length {
+               type uint32;
+               units "seconds";
+               description
+                 "The duration of this song in seconds.";
+             }
+           }   // end list 'song'
+         }   // end list 'album'
+       }  // end list 'artist'
+
+       leaf artist-count {
+          type uint32;
+          units "songs";
+          config false;
+          description "Number of artists in the library";
+       }
+       leaf album-count {
+          type uint32;
+          units "albums";
+          config false;
+          description "Number of albums in the library";
+       }
+       leaf song-count {
+          type uint32;
+          units "songs";
+          config false;
+          description "Number of songs in the library";
+       }
+     }  // end library
+
+     list playlist {
+       key name;
+
+       description
+         "Example configuration data resource";
+
+       leaf name {
+         type string;
+         description
+           "The name of the playlist.";
+       }
+       leaf description {
+         type string;
+         description
+           "A comment describing the playlist.";
+       }
+       list song {
+         key index;
+         ordered-by user;
+
+         description
+           "Example nested configuration data resource";
+
+         leaf index {    // not really needed
+           type uint32;
+           description
+             "An arbitrary integer index for this playlist song.";
+         }
+         leaf id {
+           type instance-identifier;
+           mandatory true;
+           description
+             "Song identifier. Must identify an instance of
+              /jukebox/library/artist/album/song/name.";
+         }
+       }
+     }
+
+     container player {
+       description
+         "Represents the jukebox player resource.";
+
+       leaf gap {
+         type decimal64 {
+           fraction-digits 1;
+           range "0.0 .. 2.0";
+         }
+         units "tenths of seconds";
+         description "Time gap between each song";
+       }
+     }
+   }
+
+   rpc play {
+     description "Control function for the jukebox player";
+     input {
+       leaf playlist {
+         type string;
+         mandatory true;
+         description "playlist name";
+       }
+       leaf song-number {
+         type uint32;
+         mandatory true;
+         description "Song number in playlist to play";
+       }
+     }
+   }
+}
+

tools/lint/examples/ext-data.xml

@@ -0,0 +1,10 @@
+<errors xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf">
+  <error>
+    <error-type>protocol</error-type>
+    <error-tag>data-exists</error-tag>
+    <error-path
+      xmlns:rc="urn:ietf:params:xml:ns:yang:ietf-restconf"
+      xmlns:jbox="http://example.com/ns/example-jukebox">/jbox:jukebox/jbox:library</error-path>
+    <error-message>Data already exists; cannot create new resource</error-message>
+  </error>
+</errors>