Improve error messages

.gitignore

@@ -1,3 +1,5 @@
 node_modules
 lib
 coverage
+.idea
+.DS_Store

packages/brandi/spec/binding-error.spec.ts

@@ -0,0 +1,88 @@
+import { Container, injected, token } from '../src';
+
+describe('common container error', () => {
+  const INITIAL_ERR_MSG = 'error to stop logger module from being created'
+
+  it('provides clear error when modules are functions', () => {
+    const createLoggerModule = () => {
+      throw new Error(INITIAL_ERR_MSG)
+      return {
+        log: (message: string) => {
+          // eslint-disable-next-line no-console
+          console.log(message)
+        },
+      }
+    }
+    type Logger = ReturnType<typeof createLoggerModule>
+
+    const createAdderModule = (logger: Logger) => {
+      return {
+        add: (a: number, b: number) => {
+          logger.log('adding')
+          return a + b
+        },
+      }
+    }
+    type Adder = ReturnType<typeof createAdderModule>
+
+    const TOKENS = {
+      logger: token<Logger>('logger'),
+      adder: token<Adder>('adder'),
+    }
+
+    const container = new Container()
+    injected(createAdderModule, TOKENS.logger)
+    container.bind(TOKENS.adder).toInstance(createAdderModule).inSingletonScope()
+    container.bind(TOKENS.logger).toInstance(createLoggerModule).inSingletonScope()
+
+    expect(() => {
+      container.get(TOKENS.adder)
+    }).toThrow(new Error(`Failed to get token 'adder':
+0. Failed to resolve the binding for 'adder' token.
+1. Failed to resolve the binding for 'logger' token.
+2. Failed to instantiate createLoggerModule: ${INITIAL_ERR_MSG}`))
+  })
+
+  it('provides clear error when modules are classes', () => {
+    class LoggerModule {
+      constructor() {
+        throw new Error(INITIAL_ERR_MSG)
+      }
+      // eslint-disable-next-line
+      public log(message: string) {
+        // eslint-disable-next-line no-console
+        console.log(message);
+      }
+    }
+
+    class AdderModule {
+      constructor(
+          public loggerModule: LoggerModule,
+      ) {
+        throw new Error('error to stop logger module from being created')
+      }
+      // eslint-disable-next-line
+      public add(a: number, b: number) {
+        this.loggerModule.log('adding')
+        return a + b
+      }
+    }
+
+    const TOKENS = {
+      logger: token<LoggerModule>('logger'),
+      adder: token<AdderModule>('adder'),
+    }
+
+    const container = new Container()
+    injected(AdderModule, TOKENS.logger)
+    container.bind(TOKENS.adder).toInstance(AdderModule).inSingletonScope()
+    container.bind(TOKENS.logger).toInstance(LoggerModule).inSingletonScope()
+
+    expect(() => {
+      container.get(TOKENS.adder)
+    }).toThrow(new Error(`Failed to get token 'adder':
+0. Failed to resolve the binding for 'adder' token.
+1. Failed to resolve the binding for 'logger' token.
+2. Failed to instantiate LoggerModule: ${INITIAL_ERR_MSG}`))
+  })
+})

packages/brandi/src/container/Container.ts

@@ -12,6 +12,7 @@ import {
   isInstanceResolutionScopedBinding,
   isInstanceSingletonScopedBinding,
 } from './bindings';
+import { failedToGetTokenErrorMessage, isClass } from "../lib";
 import { BindingsVault } from './BindingsVault';
 import { DependencyModule } from './DependencyModule';
 import { ResolutionCache } from './ResolutionCache';
@@ -109,7 +110,11 @@ export class Container extends DependencyModule {
     token: T,
     conditions?: ResolutionCondition[],
   ): TokenType<T> {
-    return this.resolveToken(token, conditions) as TokenType<T>;
+    try {
+      return this.resolveToken(token, conditions) as TokenType<T>;
+    } catch(e) {
+      throw new Error(`Failed to get token '${token.__d}':\n${failedToGetTokenErrorMessage(e as Error)}`)
+    }
   }
 
   private resolveTokens(
@@ -131,7 +136,13 @@ export class Container extends DependencyModule {
   ): unknown {
     const binding = this.vault.get(token, cache, conditions, target);
 
-    if (binding) return this.resolveBinding(binding, cache);
+    if (binding) {
+      try {
+        return this.resolveBinding(binding, cache);
+      } catch (e) {
+        throw new Error(`Failed to resolve the binding for '${token.__d}' token.`, { cause: e })
+      }
+    }
     if (token.__o) return undefined;
 
     throw new Error(`No matching bindings found for '${token.__d}' token.`);
@@ -231,16 +242,19 @@ export class Container extends DependencyModule {
     }
 
     try {
-      // @ts-expect-error: This expression is not callable.
-      const instance = creator(...parameters);
-      callableRegistry.set(creator, true);
-      return instance;
-    } catch {
-      // @ts-expect-error: This expression is not constructable.
-      // eslint-disable-next-line new-cap
-      const instance = new creator(...parameters);
-      callableRegistry.set(creator, false);
+      const creatorIsClass = isClass(creator)
+      const instance = creatorIsClass
+          ? // @ts-expect-error: This expression is not constructable.
+          // eslint-disable-next-line new-cap
+          new creator(...parameters)
+          // @ts-expect-error: This expression is not callable.
+          : creator(...parameters);
+      callableRegistry.set(creator, !creatorIsClass);
       return instance;
+    } catch (e) {
+      const error = e as Error
+      error.message = `Failed to instantiate ${creator.name}: ${error.message}`
+      throw error
     }
   }
 

packages/brandi/src/lib.ts

@@ -0,0 +1,13 @@
+export function isClass(v: any) {
+    return typeof v === 'function' && /^\s*class\s+/.test(v.toString());
+}
+
+export function failedToGetTokenErrorMessage(e: Error) {
+    let error = e
+    const causes: Error[] = []
+    while (error) {
+        causes.push(error)
+        error = error.cause as Error
+    }
+    return causes.map((c, idx) => `${idx}. ${c.message}`).join('\n')
+}