runes: add a way to set a budget for amount fields?

[niftynei]

Current behavior: Trying to set a budget for a rune (no invoices created over X amount, pay invoices up to X sats) fails as the pnameX restrictions are parsed as strings.

Desired behavior: pnameX where X is "amount_msat" is parsed as an integer (which would allow range assertions).

Relevant code from plugins/commando.c which causes this (L398-L432)

        if (strmap_empty(&cinfo->cached_params)) {
                const jsmntok_t *t;
                size_t i;
                
                if (cinfo->params->type == JSMN_OBJECT) {                   
                        json_for_each_obj(i, t, cinfo->params) {            
                                char *pmemname = tal_fmt(tmpctx,            
                                                         "pname%.*s",       
                                                         t->end - t->start, 
                                                         cinfo->buf + t->start);     
                                size_t off = strlen("pname");
                                /* Remove punctuation! */                   
                                for (size_t n = off; pmemname[n]; n++) {    
                                        if (cispunct(pmemname[n]))          
                                                continue;
                                        pmemname[off++] = pmemname[n];      
                                }               
                                pmemname[off++] = '\0'; 
                                strmap_add(&cinfo->cached_params, pmemname, t+1);    
                        }       
                } else if (cinfo->params->type == JSMN_ARRAY) {
                        json_for_each_arr(i, t, cinfo->params) {            
                                char *pmemname = tal_fmt(tmpctx, "parr%zu", i);              
                                strmap_add(&cinfo->cached_params, pmemname, t);
                        }
                }
        }

        ptok = strmap_get(&cinfo->cached_params, alt->fieldname);
        if (!ptok)
                return rune_alt_single_missing(ctx, alt);

        return rune_alt_single_str(ctx, alt,
                                   cinfo->buf + ptok->start,
                                   ptok->end - ptok->start);

[vincenzopalazzo]

Ok the PR is now merged #6295