Postgresql Rails + Postgres fe_sendauth：no password supplied

嗨，我正在try 将postgresql连接到我的rails项目.我正在学习测试，但我的测试没有运行，因为有一个关于密码不正确的postgresql错误:

Edmunds-MacBook-Pro:langexchange edmundmai$ rake test:units
rake aborted!
fe_sendauth: no password supplied

我已经读过了，我的pg_hba.conf文件最初是这样的:

# TYPE  DATABASE        USER            ADDRESS                 METHOD

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust
# Allow replication connections from localhost, by a user with the
# replication privilege.
#local   replication     edmundmai  

这是我的数据库.我的rails项目中的yml文件

default: &default
  adapter: postgresql
  encoding: utf8
  pool: 5
  username: edmundmai
  password: 

development:
  <<: *default
  database: project_development

test:
  <<: *default
  database: project_test

production:
  <<: *default
  database: project_production

有人知道我怎么解决这个问题吗？如果方便的话我们可以聊天.