Add TreeModel and HasSubtree implementation

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@extollo/lib",
-  "version": "0.13.10",
+  "version": "0.14.0",
   "description": "The framework library that lifts up your code.",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
@@ -47,7 +47,7 @@
     "typedoc": "^0.20.36",
     "typedoc-plugin-pages-fork": "^0.0.1",
     "typedoc-plugin-sourcefile-url": "^1.0.6",
-    "typescript": "^4.2.3",
+    "typescript": "^4.7.4",
     "uuid": "^8.3.2",
     "ws": "^8.8.0",
     "zod": "^3.11.6"

pnpm-lock.yaml

@@ -1,4 +1,4 @@
-lockfileVersion: 5.3
+lockfileVersion: 5.4
 
 specifiers:
   '@atao60/fse-cli': ^0.1.6
@@ -50,7 +50,7 @@ specifiers:
   typedoc: ^0.20.36
   typedoc-plugin-pages-fork: ^0.0.1
   typedoc-plugin-sourcefile-url: ^1.0.6
-  typescript: ^4.2.3
+  typescript: ^4.7.4
   uuid: ^8.3.2
   ws: ^8.8.0
   wtfnode: ^0.9.1
@@ -92,11 +92,11 @@ dependencies:
   reflect-metadata: 0.1.13
   rimraf: 3.0.2
   ssh2: 1.1.0
-  ts-node: 9.1.1_typescript@4.2.3
+  ts-node: 9.1.1_typescript@4.7.4
-  typedoc: 0.20.36_typescript@4.2.3
+  typedoc: 0.20.36_typescript@4.7.4
   typedoc-plugin-pages-fork: 0.0.1
   typedoc-plugin-sourcefile-url: 1.0.6_typedoc@0.20.36
-  typescript: 4.2.3
+  typescript: 4.7.4
   uuid: 8.3.2
   ws: 8.8.0
   zod: 3.11.6
@@ -106,8 +106,8 @@ devDependencies:
   '@types/mocha': 9.0.0
   '@types/sinon': 10.0.6
   '@types/wtfnode': 0.7.0
-  '@typescript-eslint/eslint-plugin': 4.26.0_942c48837be95e76bb4156c78358cdbe
+  '@typescript-eslint/eslint-plugin': 4.26.0_cgxss3zaaghocyaq4idsceujcy
-  '@typescript-eslint/parser': 4.26.0_eslint@7.27.0+typescript@4.2.3
+  '@typescript-eslint/parser': 4.26.0_4x6mfymjsyurtmri255xnln3g4
   chai: 4.3.4
   eslint: 7.27.0
   mocha: 9.1.3
@@ -160,6 +160,8 @@ packages:
     resolution: {integrity: sha512-OhsyMrqygfk5v8HmWwOzlYjJrtLaFhF34MrfG/Z73DgYCI6ojNUTUp2TYbtnjo8PegeJp12eamsNettCQjKjVw==}
     engines: {node: '>=6.0.0'}
     hasBin: true
+    dependencies:
+      '@babel/types': 7.13.14
     dev: false
 
   /@babel/runtime/7.14.6:
@@ -216,8 +218,8 @@ packages:
       dotenv: 10.0.0
       mkdirp: 1.0.4
       rimraf: 3.0.2
-      ts-node: 10.4.0_9033393ac6e1960c4e4feb229fa8feef
+      ts-node: 10.4.0_7qobpvvcbeswdxz4g6mzc6lzhy
-      typescript: 4.5.2
+      typescript: 4.7.4
       uuid: 8.3.2
     transitivePeerDependencies:
       - '@swc/core'
@@ -465,7 +467,7 @@ packages:
     resolution: {integrity: sha512-kdBHgE9+M1Os7UqWZtiLhKye5reFl8cPBYyCsP2fatwZRz7F7GdIxIHZ20Kkc0hYBfbXE+lzPOTUU1I0qgjtHA==}
     dev: true
 
-  /@typescript-eslint/eslint-plugin/4.26.0_942c48837be95e76bb4156c78358cdbe:
+  /@typescript-eslint/eslint-plugin/4.26.0_cgxss3zaaghocyaq4idsceujcy:
     resolution: {integrity: sha512-yA7IWp+5Qqf+TLbd8b35ySFOFzUfL7i+4If50EqvjT6w35X8Lv0eBHb6rATeWmucks37w+zV+tWnOXI9JlG6Eg==}
     engines: {node: ^10.12.0 || >=12.0.0}
     peerDependencies:
@@ -476,8 +478,8 @@ packages:
       typescript:
         optional: true
     dependencies:
-      '@typescript-eslint/experimental-utils': 4.26.0_eslint@7.27.0+typescript@4.2.3
+      '@typescript-eslint/experimental-utils': 4.26.0_4x6mfymjsyurtmri255xnln3g4
-      '@typescript-eslint/parser': 4.26.0_eslint@7.27.0+typescript@4.2.3
+      '@typescript-eslint/parser': 4.26.0_4x6mfymjsyurtmri255xnln3g4
       '@typescript-eslint/scope-manager': 4.26.0
       debug: 4.3.1
       eslint: 7.27.0
@@ -485,13 +487,13 @@ packages:
       lodash: 4.17.21
       regexpp: 3.1.0
       semver: 7.3.5
-      tsutils: 3.21.0_typescript@4.2.3
+      tsutils: 3.21.0_typescript@4.7.4
-      typescript: 4.2.3
+      typescript: 4.7.4
     transitivePeerDependencies:
       - supports-color
     dev: true
 
-  /@typescript-eslint/experimental-utils/4.26.0_eslint@7.27.0+typescript@4.2.3:
+  /@typescript-eslint/experimental-utils/4.26.0_4x6mfymjsyurtmri255xnln3g4:
     resolution: {integrity: sha512-TH2FO2rdDm7AWfAVRB5RSlbUhWxGVuxPNzGT7W65zVfl8H/WeXTk1e69IrcEVsBslrQSTDKQSaJD89hwKrhdkw==}
     engines: {node: ^10.12.0 || >=12.0.0}
     peerDependencies:
@@ -500,7 +502,7 @@ packages:
       '@types/json-schema': 7.0.7
       '@typescript-eslint/scope-manager': 4.26.0
       '@typescript-eslint/types': 4.26.0
-      '@typescript-eslint/typescript-estree': 4.26.0_typescript@4.2.3
+      '@typescript-eslint/typescript-estree': 4.26.0_typescript@4.7.4
       eslint: 7.27.0
       eslint-scope: 5.1.1
       eslint-utils: 3.0.0_eslint@7.27.0
@@ -509,7 +511,7 @@ packages:
       - typescript
     dev: true
 
-  /@typescript-eslint/parser/4.26.0_eslint@7.27.0+typescript@4.2.3:
+  /@typescript-eslint/parser/4.26.0_4x6mfymjsyurtmri255xnln3g4:
     resolution: {integrity: sha512-b4jekVJG9FfmjUfmM4VoOItQhPlnt6MPOBUL0AQbiTmm+SSpSdhHYlwayOm4IW9KLI/4/cRKtQCmDl1oE2OlPg==}
     engines: {node: ^10.12.0 || >=12.0.0}
     peerDependencies:
@@ -521,10 +523,10 @@ packages:
     dependencies:
       '@typescript-eslint/scope-manager': 4.26.0
       '@typescript-eslint/types': 4.26.0
-      '@typescript-eslint/typescript-estree': 4.26.0_typescript@4.2.3
+      '@typescript-eslint/typescript-estree': 4.26.0_typescript@4.7.4
       debug: 4.3.1
       eslint: 7.27.0
-      typescript: 4.2.3
+      typescript: 4.7.4
     transitivePeerDependencies:
       - supports-color
     dev: true
@@ -542,7 +544,7 @@ packages:
     engines: {node: ^8.10.0 || ^10.13.0 || >=11.10.1}
     dev: true
 
-  /@typescript-eslint/typescript-estree/4.26.0_typescript@4.2.3:
+  /@typescript-eslint/typescript-estree/4.26.0_typescript@4.7.4:
     resolution: {integrity: sha512-GHUgahPcm9GfBuy3TzdsizCcPjKOAauG9xkz9TR8kOdssz2Iz9jRCSQm6+aVFa23d5NcSpo1GdHGSQKe0tlcbg==}
     engines: {node: ^10.12.0 || >=12.0.0}
     peerDependencies:
@@ -557,8 +559,8 @@ packages:
       globby: 11.0.3
       is-glob: 4.0.1
       semver: 7.3.5
-      tsutils: 3.21.0_typescript@4.2.3
+      tsutils: 3.21.0_typescript@4.7.4
-      typescript: 4.2.3
+      typescript: 4.7.4
     transitivePeerDependencies:
       - supports-color
     dev: true
@@ -1024,7 +1026,7 @@ packages:
     engines: {node: '>=8.0.0'}
     requiresBuild: true
     dependencies:
-      nan: 2.14.2
+      nan: 2.16.0
     dev: false
     optional: true
 
@@ -1550,7 +1552,7 @@ packages:
       source-map: 0.6.1
       wordwrap: 1.0.0
     optionalDependencies:
-      uglify-js: 3.13.8
+      uglify-js: 3.17.0
     dev: false
 
   /has-flag/3.0.0:
@@ -2061,8 +2063,8 @@ packages:
     resolution: {integrity: sha512-nnbWWOkoWyUsTjKrhgD0dcz22mdkSnpYqbEjIm2nhwhuxlSkpywJmBo8h0ZqJdkp73mb90SssHkN4rsRaBAfAA==}
     dev: false
 
-  /nan/2.14.2:
+  /nan/2.16.0:
-    resolution: {integrity: sha512-M2ufzIiINKCuDfBSAUr1vWQ+vuVcA9kqx8JJUsbQi6yf1uGRyb7HfpdfUr5qLXf3B/t8dPvcjhKMmlfnP47EzQ==}
+    resolution: {integrity: sha512-UdAqHyFngu7TfQKsCBgAA6pWDkT8MAO7d0jyOecVhN5354xbLqdn8mV9Tat9gepAupm0bt2DbeaSC8vS52MuFA==}
     dev: false
     optional: true
 
@@ -2720,7 +2722,7 @@ packages:
       bcrypt-pbkdf: 1.0.2
     optionalDependencies:
       cpu-features: 0.0.2
-      nan: 2.14.2
+      nan: 2.16.0
     dev: false
 
   /standard-as-callback/2.1.0:
@@ -2870,7 +2872,7 @@ packages:
     resolution: {integrity: sha1-zCAOqyYT9BZtJ/+a/HylbUnfbrQ=}
     dev: false
 
-  /ts-node/10.4.0_9033393ac6e1960c4e4feb229fa8feef:
+  /ts-node/10.4.0_7qobpvvcbeswdxz4g6mzc6lzhy:
     resolution: {integrity: sha512-g0FlPvvCXSIO1JDF6S232P5jPYqBkRL9qly81ZgAOSU7rwI0stphCgd2kLiCrU9DjQCrJMWEqcNSjQL02s6d8A==}
     hasBin: true
     peerDependencies:
@@ -2896,11 +2898,11 @@ packages:
       create-require: 1.1.1
       diff: 4.0.2
       make-error: 1.3.6
-      typescript: 4.5.2
+      typescript: 4.7.4
       yn: 3.1.1
     dev: false
 
-  /ts-node/9.1.1_typescript@4.2.3:
+  /ts-node/9.1.1_typescript@4.7.4:
     resolution: {integrity: sha512-hPlt7ZACERQGf03M253ytLY3dHbGNGrAq9qIHWUY9XHYl1z7wYngSr3OQ5xmui8o2AaxsONxIzjafLUiWBo1Fg==}
     engines: {node: '>=10.0.0'}
     hasBin: true
@@ -2912,7 +2914,7 @@ packages:
       diff: 4.0.2
       make-error: 1.3.6
       source-map-support: 0.5.19
-      typescript: 4.2.3
+      typescript: 4.7.4
       yn: 3.1.1
     dev: false
 
@@ -2923,14 +2925,14 @@ packages:
     resolution: {integrity: sha512-N82ooyxVNm6h1riLCoyS9e3fuJ3AMG2zIZs2Gd1ATcSFjSA23Q0fzjjZeh0jbJvWVDZ0cJT8yaNNaaXHzueNjg==}
     dev: false
 
-  /tsutils/3.21.0_typescript@4.2.3:
+  /tsutils/3.21.0_typescript@4.7.4:
     resolution: {integrity: sha512-mHKK3iUXL+3UF6xL5k0PEhKRUBKPBCv/+RkEOpjRWxxx27KKRBmmA60A9pgOUvMi8GKhRMPEmjBRPzs2W7O1OA==}
     engines: {node: '>= 6'}
     peerDependencies:
       typescript: '>=2.8.0 || >= 3.2.0-dev || >= 3.3.0-dev || >= 3.4.0-dev || >= 3.5.0-dev || >= 3.6.0-dev || >= 3.6.0-beta || >= 3.7.0-dev || >= 3.7.0-beta'
     dependencies:
       tslib: 1.14.1
-      typescript: 4.2.3
+      typescript: 4.7.4
     dev: true
 
   /tweetnacl/0.14.5:
@@ -2993,10 +2995,10 @@ packages:
     peerDependencies:
       typedoc: '>=0.16.0'
     dependencies:
-      typedoc: 0.20.36_typescript@4.2.3
+      typedoc: 0.20.36_typescript@4.7.4
     dev: false
 
-  /typedoc/0.20.36_typescript@4.2.3:
+  /typedoc/0.20.36_typescript@4.7.4:
     resolution: {integrity: sha512-qFU+DWMV/hifQ9ZAlTjdFO9wbUIHuUBpNXzv68ZyURAP9pInjZiO4+jCPeAzHVcaBCHER9WL/+YzzTt6ZlN/Nw==}
     engines: {node: '>= 10.8.0'}
     hasBin: true
@@ -3014,23 +3016,16 @@ packages:
       shelljs: 0.8.4
       shiki: 0.9.3
       typedoc-default-themes: 0.12.10
-      typescript: 4.2.3
+      typescript: 4.7.4
     dev: false
 
-  /typescript/4.2.3:
+  /typescript/4.7.4:
-    resolution: {integrity: sha512-qOcYwxaByStAWrBf4x0fibwZvMRG+r4cQoTjbPtUlrWjBHbmCAww1i448U0GJ+3cNNEtebDteo/cHOR3xJ4wEw==}
+    resolution: {integrity: sha512-C0WQT0gezHuw6AdY1M2jxUO83Rjf0HP7Sk1DtXj6j1EwkQNZrHAg2XPWlq62oqEhYvONq5pkC2Y9oPljWToLmQ==}
     engines: {node: '>=4.2.0'}
     hasBin: true
-    dev: false
 
-  /typescript/4.5.2:
+  /uglify-js/3.17.0:
-    resolution: {integrity: sha512-5BlMof9H1yGt0P8/WF+wPNw6GfctgGjXp5hkblpyT+8rkASSmkUKMXrxR0Xg8ThVCi/JnHQiKXeBaEwCeQwMFw==}
+    resolution: {integrity: sha512-aTeNPVmgIMPpm1cxXr2Q/nEbvkmV8yq66F3om7X3P/cvOXQ0TMQ64Wk63iyT1gPlmdmGzjGpyLh1f3y8MZWXGg==}
-    engines: {node: '>=4.2.0'}
-    hasBin: true
-    dev: false
-
-  /uglify-js/3.13.8:
-    resolution: {integrity: sha512-PvFLMFIQHfIjFFlvAch69U2IvIxK9TNzNWt1SxZGp9JZ/v70yvqIQuiJeVPPtUMOzoNt+aNRDk4wgxb34wvEqA==}
     engines: {node: '>=0.8.0'}
     hasBin: true
     requiresBuild: true

src/cli/directive/ShellDirective.ts

@@ -63,24 +63,24 @@ export class ShellDirective extends Directive {
             globalRegistry.forceContextOverride()
 
             // Create the ts-node compiler service.
-            const replService = tsNode.createRepl()
+            // const replService = tsNode.createRepl()
-            const service = tsNode.create({...replService.evalAwarePartialHost})
+            // const service = tsNode.create({...replService.evalAwarePartialHost})
-            replService.setService(service)
+            // replService.setService(service)
 
             // We global these values into the REPL's state directly (using the `state` object
             // above), but since we're using a separate ts-node interpreter, we need to make it
             // aware of the globals using declaration syntax.
-            replService.evalCode(`
+            // replService.evalCode(`
-                declare const lib: typeof import('@extollo/lib');
+            //     declare const lib: typeof import('@extollo/lib');
-                declare const app: typeof lib['Application'];
+            //     declare const app: typeof lib['Application'];
-                declare const globalRegistry: typeof lib['globalRegistry'];
+            //     declare const globalRegistry: typeof lib['globalRegistry'];
-            `)
+            // `)
 
             // Print the welome message and start the interpreter
             this.nativeOutput(this.options.welcome)
             this.repl = repl.start({
                 // Causes the REPL to use the ts-node interpreter service:
-                eval: !this.option('js', false) ? (...args) => replService.nodeEval(...args) : undefined,
+                // eval: !this.option('js', false) ? (...args) => replService.nodeEval(...args) : undefined,
                 prompt: this.options.prompt,
                 useGlobal: true,
                 useColors: true,

src/di/Container.ts

@@ -12,12 +12,11 @@ import {
     Awaitable,
     collect,
     Collection,
-    ErrorWithContext,
     globalRegistry,
     hasOwnProperty,
     logIfDebugging,
-    withErrorContext,
 } from '../util'
+import {ErrorWithContext, withErrorContext} from '../util/error/ErrorWithContext'
 import {Factory} from './factory/Factory'
 import {DuplicateFactoryKeyError} from './error/DuplicateFactoryKeyError'
 import {ClosureFactory} from './factory/ClosureFactory'
@@ -529,7 +528,7 @@ export class Container {
                     return realized
                 }
             }, {
-                makeStack: Container.makeStack,
+                makeStack: Container.makeStack.map(x => typeof x === 'string' ? x : (x?.name || 'unknown')).toArray(),
             })
 
             if ( result ) {

src/di/decorator/injection.ts

@@ -1,5 +1,6 @@
 import 'reflect-metadata'
-import {collect, Collection, logIfDebugging} from '../../util'
+import {collect, Collection} from '../../util'
+import {logIfDebugging} from '../../util/support/debug'
 import {
     DependencyKey,
     DependencyRequirement,
@@ -100,9 +101,7 @@ export const Inject = (key?: DependencyKey, { debug = false } = {}): PropertyDec
             }
         }
 
-        if ( debug ) {
+        logIfDebugging('extollo.di.decoration', '[DEBUG] @Inject() - key:', key, 'property:', property, 'target:', target, 'target constructor:', target?.constructor, 'type:', type)
-            logIfDebugging('extollo.di.decoration', '[DEBUG] @Inject() - key:', key, 'property:', property, 'target:', target, 'target constructor:', target?.constructor, 'type:', type)
-        }
 
         Reflect.defineMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, propertyMetadata, target?.constructor || target)
     }

src/di/error/InvalidDependencyKeyError.ts

@@ -1,5 +1,5 @@
 import {DependencyKey} from '../types'
-import {ErrorWithContext} from '../../util'
+import {ErrorWithContext} from '../../util/error/ErrorWithContext'
 
 /**
  * Error thrown when a dependency key that has not been registered is passed to a resolver.

src/di/factory/AbstractFactory.ts

@@ -51,6 +51,6 @@ export abstract class AbstractFactory<T> {
             return this.token
         }
 
-        return this.token.name ?? '(unknown token)'
+        return this.token?.name ?? '(unknown token)'
     }
 }

src/di/factory/Factory.ts

@@ -6,7 +6,7 @@ import {
     Instantiable,
     PropertyDependency,
 } from '../types'
-import {Collection} from '../../util'
+import {Collection, logIfDebugging} from '../../util'
 import 'reflect-metadata'
 
 /**
@@ -58,6 +58,7 @@ export class Factory<T> extends AbstractFactory<T> {
 
         do {
             const loadedMeta = Reflect.getMetadata(DEPENDENCY_KEYS_PROPERTY_METADATA_KEY, currentToken)
+            logIfDebugging('extollo.di.injection', 'Factory.getInjectedProperties() target:', currentToken, 'loaded:', loadedMeta)
             if ( loadedMeta ) {
                 meta.concat(loadedMeta)
             }

src/orm/builder/AbstractBuilder.ts

@@ -222,17 +222,45 @@ export abstract class AbstractBuilder<T> extends AppClass {
         return this
     }
 
+    /** Apply a WHERE ... IS NULL constraint to the query. */
+    whereNull(field: string): this {
+        return this.whereRawValue(field, 'IS', 'NULL')
+    }
+
+    /** Apply a WHERE ... IS NOT NULL constraint to the query. */
+    whereNotNull(field: string): this {
+        return this.whereRawValue(field, 'IS NOT', 'NULL')
+    }
+
     /**
      * Apply a new WHERE constraint to the query, without escaping `operand`. Prefer `where()`.
      * @param field
      * @param operator
      * @param operand
      */
-    whereRaw(field: string, operator: ConstraintOperator, operand: string): this {
+    whereRawValue(field: string, operator: ConstraintOperator, operand: string): this {
         this.createConstraint('AND', field, operator, raw(operand))
         return this
     }
 
+    /**
+     * Add raw SQL as a constraint to the query.
+     * @param clause
+     */
+    whereRaw(clause: string|QuerySafeValue): this {
+        if ( !(clause instanceof QuerySafeValue) ) {
+            clause = raw(clause)
+        }
+
+        this.constraints.push(raw(clause))
+        return this
+    }
+
+    /** Apply an impossible constraint to the query, causing it to match 0 rows. */
+    whereMatchNone(): this {
+        return this.whereRaw('1=0')
+    }
+
     /**
      * Apply a new WHERE NOT constraint to the query.
      * @param field

src/orm/dialect/PostgreSQLDialect.ts

@@ -316,6 +316,8 @@ export class PostgreSQLDialect extends SQLDialect {
                     const field: string = constraint.field.split('.').map(x => `"${x}"`)
                         .join('.')
                     statements.push(`${indent}${statements.length < 1 ? '' : constraint.preop + ' '}${field} ${constraint.operator} ${this.escape(constraint.operand).value}`)
+                } else if ( constraint instanceof QuerySafeValue ) {
+                    statements.push(`${indent}${statements.length < 1 ? '' : 'AND '}${constraint.toString()}`)
                 }
             }
 

src/orm/dialect/SQLDialect.ts

@@ -14,7 +14,7 @@ export type EscapeValue = null | undefined | string | number | boolean | Date |
 export type EscapeValueObject = { [field: string]: EscapeValue }
 
 /**
- * A wrapper class whose value is save to inject directly into a query.
+ * A wrapper class whose value is safe to inject directly into a query.
  */
 export class QuerySafeValue {
     constructor(

src/orm/index.ts

@@ -20,12 +20,14 @@ export * from './model/ModelResultIterable'
 export * from './model/events'
 export * from './model/Model'
 export * from './model/ModelSerializer'
+export * from './model/TreeModel'
 
 export * from './model/relation/RelationBuilder'
 export * from './model/relation/Relation'
 export * from './model/relation/HasOneOrMany'
 export * from './model/relation/HasOne'
 export * from './model/relation/HasMany'
+export * from './model/relation/HasSubtree'
 export * from './model/relation/decorators'
 
 export * from './model/scope/Scope'

src/orm/model/Model.ts

@@ -19,7 +19,7 @@ import {HasOne} from './relation/HasOne'
 import {HasMany} from './relation/HasMany'
 import {HasOneOrMany} from './relation/HasOneOrMany'
 import {Scope, ScopeClosure} from './scope/Scope'
-import {LocalBus} from '../../support/bus/LocalBus'
+import {LocalBus} from '../../support/bus/LocalBus'  // need the specific import to prevent circular dependencies
 import {ModelEvent} from './events/ModelEvent'
 
 /**
@@ -149,7 +149,8 @@ export abstract class Model<T extends Model<T>> extends LocalBus<ModelEvent<T>>
      * ```
      */
     public static query<T2 extends Model<T2>>(): ModelBuilder<T2> {
-        const builder = <ModelBuilder<T2>> Container.getContainer().make<ModelBuilder<T2>>(ModelBuilder, this)
+        const di = Container.getContainer()
+        const builder = <ModelBuilder<T2>> di.make<ModelBuilder<T2>>(ModelBuilder, this)
         const source: QuerySource = this.querySource()
 
         builder.connection(this.getConnection())
@@ -164,35 +165,17 @@ export abstract class Model<T extends Model<T>> extends LocalBus<ModelEvent<T>>
             builder.field(field.databaseKey)
         })
 
-        if ( Array.isArray(this.prototype.with) ) {
+        const inst = di.make<T2>(this)
+        if ( Array.isArray(inst.with) ) {
             // Try to get the eager-loaded relations statically, if possible
-            for (const relation of this.prototype.with) {
+            for (const relation of inst.with) {
                 // eslint-disable-next-line @typescript-eslint/ban-ts-comment
                 // @ts-ignore
                 builder.with(relation)
             }
-        } else if ( this.constructor.length < 1 ) {
-            // Otherwise, if we can instantiate the model without any arguments,
-            // do that and get the eager-loaded relations directly.
-            const inst = Container.getContainer().make<Model<any>>(this)
-            if ( Array.isArray(inst.with) ) {
-                for (const relation of inst.with) {
-                    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
-                    // @ts-ignore
-                    builder.with(relation)
-                }
-            }
-        }
-
-        if ( this.prototype.scopes ) {
-            // Same thing here. Try to get the scopes statically, if possible
-            builder.withScopes(this.prototype.scopes)
-        } else if ( this.constructor.length < 1 ) {
-            // Otherwise, try to instantiate the model if possible and load the scopes that way
-            const inst = Container.getContainer().make<Model<any>>(this)
-            builder.withScopes(inst.scopes)
         }
 
+        builder.withScopes(inst.scopes)
 
         return builder
     }
@@ -1008,13 +991,13 @@ export abstract class Model<T extends Model<T>> extends LocalBus<ModelEvent<T>>
         }
 
         if ( typeof relFn === 'function' ) {
-            const rel = relFn.apply(relFn, this)
+            const rel = relFn.bind(this)()
             if ( rel instanceof Relation ) {
                 return rel
             }
         }
 
-        throw new TypeError(`Cannot get relation of name: ${name}. Method does not return a Relation.`)
+        throw new TypeError(`Cannot get relation of name: ${String(name)}. Method does not return a Relation.`)
     }
 
     /**

src/orm/model/ModelBuilder.ts

@@ -78,7 +78,7 @@ export class ModelBuilder<T extends Model<T>> extends AbstractBuilder<T> {
      */
     public with(relationName: keyof T): this {
         if ( !this.eagerLoadRelations.includes(relationName) ) {
-            // Try to load the Relation so we fail if the name is invalid
+            // Try to load the Relation, so we fail if the name is invalid
             this.make<T>(this.ModelClass).getRelation(relationName)
             this.eagerLoadRelations.push(relationName)
         }
@@ -86,6 +86,15 @@ export class ModelBuilder<T extends Model<T>> extends AbstractBuilder<T> {
         return this
     }
 
+    /**
+     * Prevent a relation from being eager-loaded.
+     * @param relationName
+     */
+    public without(relationName: keyof T): this {
+        this.eagerLoadRelations = this.eagerLoadRelations.filter(name => name !== relationName)
+        return this
+    }
+
     /**
      * Remove all global scopes from this query.
      */

src/orm/model/ModelResultIterable.ts

@@ -70,6 +70,11 @@ export class ModelResultIterable<T extends Model<T>> extends AbstractResultItera
      * @protected
      */
     protected async processEagerLoads(results: Collection<T>): Promise<void> {
+        if ( results.isEmpty() ) {
+            // Nothing to load relations for, so no reason to perform more queries
+            return
+        }
+
         const eagers = this.builder.getEagerLoadedRelations()
         const model = this.make<T>(this.ModelClass)
 
@@ -78,9 +83,10 @@ export class ModelResultIterable<T extends Model<T>> extends AbstractResultItera
 
             const relation = model.getRelation(name)
             const select = relation.buildEagerQuery(this.builder, results)
+            const resultCount = await select.get().count()
 
-            const allRelated = await select.get().collect()
+            const allRelated = resultCount ? await select.get().collect() : collect()
-            allRelated.each(result => {
+            results.each(result => {
                 const resultRelation = result.getRelation(name as any)
                 const resultRelated = resultRelation.matchResults(allRelated as any)
                 resultRelation.setValue(resultRelated as any)

src/orm/model/TreeModel.ts

@@ -0,0 +1,88 @@
+import {Model} from './Model'
+import {Collection, Maybe} from '../../util'
+import {HasSubtree} from './relation/HasSubtree'
+import {Related} from './relation/decorators'
+
+/**
+ * Model implementation with helpers for querying tree-structured data.
+ *
+ * This works by using a modified pre-order traversal to number the tree nodes
+ * with a left- and right-side numbers. For example:
+ *
+ * ```txt
+ *                     (1) A (14)
+ *                         |
+ *       (2) B (9)    (10) C (11)    (12) D (14)
+ *           |
+ * (3) E (6)   (7) G (8)
+ *     |
+ * (4) F (5)
+ * ```
+ *
+ * These numbers are stored, by default, in `left_num` and `right_num` columns.
+ * The `subtree()` method returns a `HasSubtree` relation which loads the subtree
+ * of a model and recursively nests the nodes.
+ *
+ * You can use the `children()` helper method to get a collection of the immediate
+ * children of this node, which also have the subtree set.
+ *
+ * To query the model without loading the entire subtree, use the `without()`
+ * method on the `ModelBuilder`. For example:
+ *
+ * ```ts
+ * MyModel.query<MyModel>().without('subtree')
+ * ```
+ */
+export abstract class TreeModel<T extends TreeModel<T>> extends Model<T> {
+
+    /** The table column where the left tree number is stored. */
+    public static readonly leftTreeField = 'left_num'
+
+    /** The table column where the right tree number is stored. */
+    public static readonly rightTreeField = 'right_num'
+
+    /**
+     * @override to eager-load the subtree by default
+     * @protected
+     */
+    protected with: (keyof T)[] = ['subtree']
+
+    /** Get the left tree number for this model. */
+    public leftTreeNum(): Maybe<number> {
+        const ctor = this.constructor as typeof TreeModel
+        return this.originalSourceRow?.[ctor.leftTreeField]
+    }
+
+    /** Get the right tree number for this model. */
+    public rightTreeNum(): Maybe<number> {
+        const ctor = this.constructor as typeof TreeModel
+        return this.originalSourceRow?.[ctor.rightTreeField]
+    }
+
+    /** Returns true if this node has no children. */
+    public isLeaf(): boolean {
+        const left = this.leftTreeNum()
+        const right = this.rightTreeNum()
+        return Boolean(left && right && (right - left === 1))
+    }
+
+    /** Returns true if the given `node` exists within the subtree of this node. */
+    public contains(node: this): boolean {
+        const num = node.leftTreeNum()
+        const left = this.leftTreeNum()
+        const right = this.rightTreeNum()
+        return Boolean(num && left && right && (left < num && right > num))
+    }
+
+    /** The subtree nodes of this model, recursively nested. */
+    @Related()
+    public subtree(): HasSubtree<T> {
+        const ctor = this.constructor as typeof TreeModel
+        return this.make<HasSubtree<T>>(HasSubtree, this, ctor.leftTreeField)
+    }
+
+    /** Get the immediate children of this model. */
+    public children(): Collection<T> {
+        return this.subtree().getValue()
+    }
+}

src/orm/model/relation/HasOneOrMany.ts

@@ -59,7 +59,7 @@ export abstract class HasOneOrMany<T extends Model<T>, T2 extends Model<T2>, V e
     public applyScope(where: AbstractBuilder<T2>): void {
         where.where(subq => {
             subq.where(this.qualifiedForeignKey, '=', this.parentValue)
-                .whereRaw(this.qualifiedForeignKey, 'IS NOT', 'NULL')
+                .whereNotNull(this.qualifiedForeignKey)
         })
     }
 

src/orm/model/relation/HasSubtree.ts

@@ -0,0 +1,147 @@
+import {TreeModel} from '../TreeModel'
+import {Relation, RelationNotLoadedError} from './Relation'
+import {collect, Collection, Maybe} from '../../../util'
+import {RelationBuilder} from './RelationBuilder'
+import {raw} from '../../dialect/SQLDialect'
+import {AbstractBuilder} from '../../builder/AbstractBuilder'
+import {ModelBuilder} from '../ModelBuilder'
+
+/**
+ * A relation that recursively loads the subtree of a model using
+ * modified preorder traversal.
+ */
+export class HasSubtree<T extends TreeModel<T>> extends Relation<T, T, Collection<T>> {
+
+    /**
+     * When the relation is loaded, the immediate children of the node.
+     * @protected
+     */
+    protected instances: Maybe<Collection<T>>
+
+    constructor(
+        protected readonly model: T,
+        protected readonly leftTreeField: string,
+    ) {
+        super(model, model)
+    }
+
+    protected get parentValue(): any {
+        return this.model.key()
+    }
+
+    public query(): RelationBuilder<T> {
+        return this.builder()
+            .select(raw('*'))
+            .orderByAscending(this.leftTreeField)
+    }
+
+    public applyScope(where: AbstractBuilder<T>): void {
+        const left = this.model.leftTreeNum()
+        const right = this.model.rightTreeNum()
+        if ( !left || !right ) {
+            where.whereMatchNone()
+            return
+        }
+
+        where.where(this.leftTreeField, '>', left)
+            .where(this.leftTreeField, '<', right)
+    }
+
+    public buildEagerQuery(parentQuery: ModelBuilder<T>, result: Collection<T>): ModelBuilder<T> {
+        const query = this.model.query().without('subtree')
+
+        if ( result.isEmpty() ) {
+            return query.whereMatchNone()
+        }
+
+        result.each(inst => {
+            const left = inst.leftTreeNum()
+            const right = inst.rightTreeNum()
+            if ( !left || !right ) {
+                return
+            }
+
+            query.where(where => {
+                where.where(this.leftTreeField, '>', left)
+                    .where(this.leftTreeField, '<', right)
+            })
+        })
+
+        return query
+    }
+
+    public matchResults(possiblyRelated: Collection<T>): Collection<T> {
+        const modelLeft = this.model.leftTreeNum()
+        const modelRight = this.model.rightTreeNum()
+        if ( !modelLeft || !modelRight ) {
+            return collect()
+        }
+
+        return possiblyRelated.filter(inst => {
+            const instLeft = inst.leftTreeNum()
+            return Boolean(instLeft && instLeft > modelLeft && instLeft < modelRight)
+        })
+    }
+
+    public setValue(related: Collection<T>): void {
+        // `related` contains a flat collection of the subtree nodes, ordered by left key ascending
+        // We will loop through the related nodes and recursively call `setValue` for our immediate
+        // children to build the tree.
+
+        type ReduceState = {
+            currentChild: T,
+            currentSubtree: Collection<T>,
+        }
+
+        const children = this.instances = collect()
+        const firstChild = related.pop()
+        if ( !firstChild ) {
+            return
+        }
+
+        const finalState = related.reduce<ReduceState>((state: ReduceState, node: T) => {
+            if ( state.currentChild.contains(node) ) {
+                // `node` belongs in the subtree of `currentChild`, not this node
+                state.currentSubtree.push(node)
+                return state
+            }
+
+            // We've hit the end of the subtree for `currentChild`, so set the child's
+            // subtree relation value and move on to the next child.
+            state.currentChild.subtree().setValue(state.currentSubtree)
+            children.push(state.currentChild)
+
+            return {
+                currentChild: node,
+                currentSubtree: collect(),
+            }
+        }, {
+            currentChild: firstChild,
+            currentSubtree: collect(),
+        })
+
+        // Do this one last time, since the reducer isn't called for the last node in the collection
+        if ( finalState ) {
+            finalState.currentChild.subtree().setValue(finalState.currentSubtree)
+            children.push(finalState.currentChild)
+        }
+
+        this.instances = children.sortBy(inst => inst.getOriginalValues()?.[this.leftTreeField])
+    }
+
+    public getValue(): Collection<T> {
+        if ( !this.instances ) {
+            throw new RelationNotLoadedError()
+        }
+
+        return this.instances
+    }
+
+    public isLoaded(): boolean {
+        return Boolean(this.instances)
+    }
+
+    public get(): Promise<Collection<T>> {
+        return this.fetch().collect()
+    }
+}

src/orm/model/relation/Relation.ts

@@ -59,7 +59,9 @@ export abstract class Relation<T extends Model<T>, T2 extends Model<T2>, V exten
 
     /** Get a collection of the results of this relation. */
     public fetch(): ResultCollection<T2> {
-        return this.query().get()
+        return this.query()
+            .where(where => this.applyScope(where))
+            .get()
     }
 
     /** Resolve the result of this relation. */
@@ -106,6 +108,9 @@ export abstract class Relation<T extends Model<T>, T2 extends Model<T2>, V exten
 
     /** Get a new builder instance for this relation. */
     public builder(): RelationBuilder<T2> {
-        return this.make(RelationBuilder, this)
+        const relatedCtor = this.related.constructor as typeof Model
+        return this.make<RelationBuilder<T2>>(RelationBuilder, this)
+            .connection(relatedCtor.getConnection())
+            .from(relatedCtor.tableName())
     }
 }

src/orm/types.ts

@@ -77,7 +77,7 @@ export function isConstraintItem(what: unknown): what is ConstraintItem {
 /**
  * Type alias for something that can be either a single constraint or a group of them.
  */
-export type Constraint = ConstraintItem | ConstraintGroup
+export type Constraint = ConstraintItem | ConstraintGroup | QuerySafeValue
 
 /**
  * Type alias for an item that refers to a field on a table.

src/util/collection/Collection.ts

@@ -14,11 +14,11 @@ type MaybeCollectionIndex = CollectionIndex | undefined
 type ComparisonFunction<T> = (item: CollectionItem<T>, otherItem: CollectionItem<T>) => number
 
 import { WhereOperator, applyWhere, whereMatch } from './where'
-import {Awaitable, Awaited, Either, isLeft, Maybe, MethodsOf, right, unright} from '../support/types'
+import {Awaitable, Awaited, Either, isLeft, Maybe, MethodsOf, MethodType, right, unright} from '../support/types'
 import {AsyncCollection} from './AsyncCollection'
 import {ArrayIterable} from './ArrayIterable'
 
-const collect = <T>(items: CollectionItem<T>[]): Collection<T> => Collection.collect(items)
+const collect = <T>(items: CollectionItem<T>[] = []): Collection<T> => Collection.collect(items)
 const toString = (item: unknown): string => String(item)
 
 export {
@@ -381,8 +381,12 @@ class Collection<T> {
      * @param method
      * @param params
      */
-    mapCall<T2 extends MethodsOf<T>>(method: T2, ...params: Parameters<T[T2]>): Collection<ReturnType<T[T2]>> {
+    mapCall<T2 extends MethodsOf<T>>(method: T2, ...params: Parameters<MethodType<T, T2>>): Collection<ReturnType<MethodType<T, T2>>> {
-        return this.map(x => x[method](...params))
+        // This is dumb, but I'm not sure how else to resolve it. The types check out, but TypeScript loses track of the fact that
+        // typeof x[method] === MethodType<T, T2>, so it assumes we're indexing an object incorrectly.
+        // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+        // @ts-ignore
+        return this.map((x: T) => x[method](...params))
     }
 
     /**
@@ -390,7 +394,7 @@ class Collection<T> {
      * @param method
      * @param params
      */
-    async awaitMapCall<T2 extends MethodsOf<T>>(method: T2, ...params: Parameters<T[T2]>): Promise<Collection<Awaited<ReturnType<T[T2]>>>> {
+    async awaitMapCall<T2 extends MethodsOf<T>>(method: T2, ...params: Parameters<MethodType<T, T2>>): Promise<Collection<Awaited<ReturnType<MethodType<T, T2>>>>> {
         return this.mapCall(method, ...params).awaitAll()
     }
 

src/util/support/types.ts

@@ -73,6 +73,10 @@ export type MethodsOf<T, TMethod = (...args: any[]) => any> = {
     [K in keyof T]: T[K] extends TMethod ? K : never
 }[keyof T]
 
+export type MethodType<TClass, TKey extends keyof TClass, TMethod = (...args: any[]) => any> = {
+    [K in keyof TClass]: TClass[K] extends TMethod ? TClass[K] : never
+}[TKey]
+
 export type Awaited<T> = T extends PromiseLike<infer U> ? U : T
 
 export type Integer = TypeTag<'@extollo/lib.Integer'> & number