Add required flag to DIVE_PARAM

Pipelines can now mark a DIVE_PARAM as required by adding `required`
as one of the type props in the comment header:

    # DIVE_PARAM ["My label", float, required]
    :my:key = 0.5

The parser strips it from `type_props` and sets `required: true` on
the param. PipelineParamsDialog shows a red `*` on the label and
blocks the Run button via vuetify form validation if the field is
empty. Both the desktop common.ts parser and the server
pipeline_discovery.py parser handle the keyword.

Author: mattdawkins

client/dive-common/apispec.ts

@@ -42,6 +42,8 @@ interface DiveParam {
   type_props?: string[];
   key: string;
   default: string;
+  /** True if the user must supply a value before the pipeline can run. */
+  required?: boolean;
 }
 
 interface PipeMetadata {

client/dive-common/components/PipelineParamsDialog.vue

@@ -55,8 +55,14 @@ export default defineComponent({
       strictlyPositive: (value: string | number) => Number(value) > 0 || 'Please enter a number > 0',
     };
 
-    function getRules(type: PipelineParamType): ValidationRule[] {
-      const res = [];
+    function getRules(type: PipelineParamType, required = false): ValidationRule[] {
+      const res: ValidationRule[] = [];
+      if (required) {
+        res.push((value) => {
+          if (value === undefined || value === null || value === '') return 'Required';
+          return true;
+        });
+      }
       if (type.includes('int')) {
         res.push(rules.integer);
       }
@@ -131,7 +137,7 @@ export default defineComponent({
                 :for="`input-${param.key}`"
                 class="text-caption font-weight-bold text-uppercase text--secondary"
               >
-                {{ param.label }}
+                {{ param.label }}<span v-if="param.required" class="error--text"> *</span>
               </label>
             </div>
 
@@ -157,7 +163,7 @@ export default defineComponent({
                 hide-details="auto"
                 class="mt-1"
                 :min="param.type === 'int' ? 'none' : 0"
-                :rules="getRules(param.type)"
+                :rules="getRules(param.type, param.required)"
               />
             </template>
 
@@ -171,7 +177,7 @@ export default defineComponent({
                 hide-details="auto"
                 class="mt-1"
                 :min="param.type === 'float' ? 'none' : 0"
-                :rules="getRules(param.type)"
+                :rules="getRules(param.type, param.required)"
               />
             </template>
 
@@ -193,7 +199,7 @@ export default defineComponent({
                       :min="param.type_props?.at(0) || 0"
                       :max="param.type_props?.at(1) || 100"
                       :step="param.type_props?.at(2) || 1"
-                      :rules="getRules(param.type)"
+                      :rules="getRules(param.type, param.required)"
                       outlined
                       hide-details
                     />
@@ -211,6 +217,7 @@ export default defineComponent({
               dense
               hide-details="auto"
               class="mt-1"
+              :rules="getRules(param.type, param.required)"
             />
           </div>
         </v-form>

client/platform/desktop/backend/native/common.ts

@@ -109,7 +109,11 @@ async function extractPipeMetadata(filePath: string): Promise<PipeMetadata> {
         const [, label, rawArgs] = diveMatch;
         const args = rawArgs.split(',').map((arg) => arg.trim());
         const type: PipelineParamType = args[0] as PipelineParamType;
-        const pipelineTypeArgs = args.slice(1);
+        const restArgs = args.slice(1);
+        // `required` is a flag keyword — strip it from type_props,
+        // everything else stays positional for the type.
+        const isRequired = restArgs.some((a) => a.toLowerCase() === 'required');
+        const pipelineTypeArgs = restArgs.filter((a) => a.toLowerCase() !== 'required');
 
         const paramLineMatch = trimmed.match(/^(?:relativepath\s+)?(?::)?([\w:-]+)\s*=?\s*([^#]+)/i);
         if (paramLineMatch) {
@@ -122,6 +126,7 @@ async function extractPipeMetadata(filePath: string): Promise<PipeMetadata> {
             type_props: pipelineTypeArgs,
             key: fullKey,
             default: defaultValue,
+            ...(isRequired ? { required: true } : {}),
           });
         }
       }

server/dive_tasks/pipeline_discovery.py

@@ -72,7 +72,11 @@ def extract_pipe_metadata(file_path: Path) -> PipeMetadata:
                     label, raw_args = dive_match.groups()
                     args = [arg.strip() for arg in raw_args.split(',')]
                     param_type = args[0]
-                    pipeline_type_args = args[1:]
+                    rest_args = args[1:]
+                    # `required` is a flag keyword — strip it from type_props,
+                    # everything else stays positional for the type.
+                    is_required = any(a.lower() == 'required' for a in rest_args)
+                    pipeline_type_args = [a for a in rest_args if a.lower() != 'required']
 
                     param_line_match = re.match(r'^(?:relativepath\s+)?(?::)?([\w:-]+)\s*=?\s*([^#]+)', trimmed,
                                                 re.IGNORECASE)
@@ -81,13 +85,16 @@ def extract_pipe_metadata(file_path: Path) -> PipeMetadata:
                         default_val = param_line_match.group(2).strip()
                         full_key = ":".join(context_stack + [local_key])
 
-                        metadata["diveParams"].append({
+                        param_dict = {
                             "label": label,
                             "type": param_type,
                             "type_props": pipeline_type_args,
                             "key": full_key,
-                            "default": default_val
-                        })
+                            "default": default_val,
+                        }
+                        if is_required:
+                            param_dict["required"] = True
+                        metadata["diveParams"].append(param_dict)
 
                 # --- Description extraction (Multiline) ---
                 desc_start_match = re.match(r'^#\s*Description:\s*(.*)', line_raw, re.IGNORECASE)

server/dive_utils/types.py

@@ -59,12 +59,14 @@ class Config:
         extra = 'forbid'
 
 
-class DiveParam(TypedDict):
+class DiveParam(TypedDict, total=False):
     label: str
     type: str
     type_props: list[str]
     key: str
     default: str
+    # True if the pipeline can't run until the user supplies a value
+    required: bool
 
 
 class PipeMetadata(TypedDict):